feat(merge): auto-resolve all field conflicts deterministically (bd-6l8)

Implement deterministic auto-resolve rules for all merge conflicts:
- Title/Description: side with latest updated_at wins
- Notes: concatenate both sides with separator
- Priority: higher priority wins (lower number)
- IssueType: local (left) wins
- Status: closed wins (existing)

Also fixed bug in isTimeAfter where invalid t1 incorrectly beat valid t2.

Removed unused conflict generation code (hasConflict, makeConflict,
makeConflictWithBase, issuesEqual, cmp import).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.beads/issues.jsonl

@@ -23,7 +23,7 @@
 {"id":"bd-5bj","title":"Registry has cross-process race condition","description":"The global daemon registry (~/.beads/registry.json) can be corrupted when multiple daemons from different workspaces write simultaneously.\n\n**Root cause:**\n- Registry uses an in-process mutex but no file-level locking\n- Register() and Unregister() release the mutex between read and write\n- Multiple daemon processes can interleave their read-modify-write cycles\n\n**Evidence:**\nFound registry.json with double closing bracket: `]]` instead of `]`\n\n**Fix options:**\n1. Use file locking (flock/fcntl) around the entire read-modify-write cycle\n2. Use atomic write pattern (write to temp file, rename)\n3. Both (belt and suspenders)\n\n**Files:**\n- internal/daemon/registry.go:46-64 (readEntries)\n- internal/daemon/registry.go:67-87 (writeEntries)\n- internal/daemon/registry.go:90-108 (Register - the race window)","status":"closed","priority":2,"issue_type":"bug","created_at":"2025-11-27T13:55:50.426188-08:00","updated_at":"2025-11-27T14:07:06.22622-08:00","closed_at":"2025-11-27T14:07:06.22622-08:00"}
 {"id":"bd-63l","title":"bd hooks install fails in git worktrees","description":"When bd is used in a git worktree, bd hooks install fails with 'mkdir .git: not a directory' because .git is a file (gitdir pointer) not a directory. Beads should detect and follow the .git gitdir pointer to install hooks in the correct location. This blocks normal worktree workflows.\n\n## Symptoms of this bug:\n- Git hooks don't install automatically\n- Auto-sync doesn't run (5-second debounce)\n- Hash mismatch warnings in bd output\n- Daemon fails to start with 'auto_start_failed'\n\n## Workaround:\nUse `git rev-parse --git-dir` to find the actual hooks directory and copy hooks manually:\n```bash\nmkdir -p $(git rev-parse --git-dir)/hooks\ncp -r .beads-hooks/* $(git rev-parse --git-dir)/hooks/\n```","status":"closed","priority":1,"issue_type":"bug","created_at":"2025-11-29T00:27:59.111163003-07:00","updated_at":"2025-11-29T23:20:04.196608-08:00","closed_at":"2025-11-29T23:20:01.394894-08:00"}
 {"id":"bd-6ic","title":"Second worktree test","description":"","status":"closed","priority":2,"issue_type":"task","created_at":"2025-11-30T00:40:28.768125-08:00","updated_at":"2025-11-30T00:40:58.06615-08:00","closed_at":"2025-11-30T00:40:58.06615-08:00"}
-{"id":"bd-6l8","title":"Auto-resolve all field conflicts in merge.go","description":"Eliminate manual conflict resolution by adding deterministic auto-resolve rules for all fields:\n\n- Priority: higher priority wins (lower number = more urgent)\n- IssueType: local wins\n- Notes: concatenate both sides with separator\n- Title: side with latest updated_at on the issue wins\n- Description: side with latest updated_at on the issue wins\n\nCurrently true conflicts (both sides changed same field to different values) fail sync. With this change, NO conflicts ever require manual resolution.\n\nLocation: internal/merge/merge.go\nParent issue: bd-3s8","status":"open","priority":2,"issue_type":"task","created_at":"2025-12-02T19:30:59.244181-08:00","updated_at":"2025-12-02T19:30:59.244181-08:00"}
+{"id":"bd-6l8","title":"Auto-resolve all field conflicts in merge.go","description":"Eliminate manual conflict resolution by adding deterministic auto-resolve rules for all fields:\n\n- Priority: higher priority wins (lower number = more urgent)\n- IssueType: local wins\n- Notes: concatenate both sides with separator\n- Title: side with latest updated_at on the issue wins\n- Description: side with latest updated_at on the issue wins\n\nCurrently true conflicts (both sides changed same field to different values) fail sync. With this change, NO conflicts ever require manual resolution.\n\nLocation: internal/merge/merge.go\nParent issue: bd-3s8","status":"closed","priority":2,"issue_type":"task","created_at":"2025-12-02T19:30:59.244181-08:00","updated_at":"2025-12-02T19:49:51.570143-08:00","closed_at":"2025-12-02T19:49:51.570143-08:00"}
 {"id":"bd-736d","title":"Refactor path canonicalization into helper function","description":"The path canonicalization logic (filepath.Abs + EvalSymlinks) is duplicated in 3 places:\n- beads.go:131-137 (BEADS_DIR handling)\n- cmd/bd/main.go:446-451 (--no-db cleanup)\n- cmd/bd/nodb.go:26-31 (--no-db initialization)\n\nRefactoring suggestion:\nExtract to a helper function like:\n  func canonicalizePath(path string) string\n\nThis would:\n- Reduce code duplication\n- Make the logic easier to maintain\n- Ensure consistent behavior across all path handling\n\nRelated to bd-e16b implementation.","status":"closed","priority":3,"issue_type":"chore","created_at":"2025-11-02T18:33:47.727443-08:00","updated_at":"2025-11-25T22:27:33.738672-08:00","closed_at":"2025-11-25T22:27:33.738672-08:00"}
 {"id":"bd-73u","title":"Refactor daemon local-only sync functions to reduce duplication","description":"PR #433 added three new local-only sync functions (createLocalSyncFunc, createLocalExportFunc, createLocalAutoImportFunc) that are largely copy-paste of existing ones with git operations removed. Refactor to use a single implementation with a skipGit bool parameter or extract shared logic into helper functions to reduce ~200 lines of duplication.","status":"closed","priority":3,"issue_type":"task","created_at":"2025-12-01T17:38:02.632264-08:00","updated_at":"2025-12-01T21:08:11.952459-08:00","closed_at":"2025-12-01T21:08:11.952459-08:00","close_reason":"Refactored createSyncFunc and createLocalSyncFunc to use shared performSync implementation. Reduced 54 lines of duplication."}
 {"id":"bd-7ch","title":"Auto-push after merge with safety check","description":"Make bd sync a true one-command solution by auto-pushing after successful content merge.\n\nBehavior:\n- After successful content merge, auto-push by default\n- Safety check: detect when \u003e50% issues vanished AND \u003e5 existed before\n- On safety check trigger: warn but still push (do not block happy path)\n\nVanished means issues removed from issues.jsonl entirely, NOT status=closed (closed is legitimate swarm completion).\n\nLocation: internal/syncbranch/worktree.go\nParent issue: bd-3s8","status":"open","priority":2,"issue_type":"task","created_at":"2025-12-02T19:30:59.540636-08:00","updated_at":"2025-12-02T19:30:59.540636-08:00"}
@@ -31,6 +31,7 @@
 {"id":"bd-8a5","title":"Refactor: deduplicate FindJSONLInDir and FindJSONLPath","description":"## Background\n\nAfter fixing bd-tqo, we now have two nearly identical functions for finding the JSONL file:\n- `autoimport.FindJSONLInDir(dbDir string)` in internal/autoimport/autoimport.go\n- `beads.FindJSONLPath(dbPath string)` in internal/beads/beads.go\n\nBoth implement the same logic:\n1. Prefer issues.jsonl\n2. Fall back to beads.jsonl for legacy support\n3. Skip deletions.jsonl and merge artifacts\n4. Default to issues.jsonl if nothing found\n\n## Problem\n\nCode duplication means bug fixes need to be applied in multiple places (as we just experienced with bd-tqo).\n\n## Proposed Solution\n\nExtract shared logic to a utility package that both can import. Options:\n1. Create `internal/jsonlpath` package with the core logic\n2. Have `autoimport` import `beads` and call `FindJSONLPath` (but APIs differ slightly)\n3. Move to `internal/utils` if appropriate\n\nNeed to verify no import cycles would be created.\n\n## Affected Files\n- internal/autoimport/autoimport.go\n- internal/beads/beads.go","status":"closed","priority":4,"issue_type":"task","created_at":"2025-11-26T23:45:18.974339-08:00","updated_at":"2025-11-29T22:06:06.330185-08:00","closed_at":"2025-11-28T23:07:08.912247-08:00"}
 {"id":"bd-8an","title":"bd import auto-detects wrong prefix from directory name instead of issue IDs","description":"When importing issues.jsonl into a fresh database, 'bd import' prints:\n\n  ✓ Initialized database with prefix 'beads' (detected from issues)\n\nBut the issues all have prefix 'bd-' (e.g., bd-03r). It appears to be detecting the prefix from the directory name (.beads/) rather than from the actual issue IDs in the JSONL.\n\nThis causes import to fail with:\n  validate ID prefix for bd-03r: issue ID 'bd-03r' does not match configured prefix 'beads'\n\nWorkaround: Run 'bd config set issue_prefix bd' before import, or use 'bd init --prefix bd'.","status":"closed","priority":2,"issue_type":"bug","created_at":"2025-11-26T22:28:01.582564-08:00","updated_at":"2025-11-28T22:17:12.607316-08:00","closed_at":"2025-11-27T22:38:48.971617-08:00"}
 {"id":"bd-8ib","title":"Update git hooks to be sync.branch aware","description":"## Problem\n\nThe pre-push hook blocks pushes when .beads/issues.jsonl has uncommitted changes. But with sync.branch configured, those changes are intentionally NOT committed to main - they go to the sync branch via worktree.\n\n## Current Behavior\n\n1. User configures sync.branch=beads-sync\n2. bd sync commits changes to beads-sync via worktree  \n3. Local .beads/issues.jsonl is updated (needed for import)\n4. git push to main triggers pre-push hook\n5. Hook sees uncommitted .beads changes and blocks push\n6. User must use --no-verify to push\n\n## Expected Behavior\n\nWhen sync.branch is configured, the pre-push hook should:\n1. Check if sync.branch is set (bd config get sync.branch)\n2. If set, skip the .beads uncommitted check OR\n3. Verify changes are committed to the sync branch instead\n\n## Affected Files\n\n- examples/git-hooks/pre-push\n- examples/git-hooks/pre-commit (may also need update)\n\n## Workaround\n\nUse git push --no-verify","status":"closed","priority":2,"issue_type":"task","created_at":"2025-11-30T00:43:40.991951-08:00","updated_at":"2025-11-30T11:12:09.91242-08:00","closed_at":"2025-11-30T11:12:09.91242-08:00"}
+{"id":"bd-8nz","title":"Merge timestamp tie-breaker should prefer local (left)","description":"In mergeFieldByUpdatedAt, when timestamps are exactly equal, right wins. For consistency with IssueType (where local/left wins), equal timestamps should prefer left. Minor inconsistency.","status":"open","priority":4,"issue_type":"task","created_at":"2025-12-02T20:14:59.898345-08:00","updated_at":"2025-12-02T20:14:59.898345-08:00"}
 {"id":"bd-8q0","title":"Add Claude Code web installation docs to README","description":"GH #439 reported installation issues in Claude Code web environment. The go install fallback works, but users need guidance. Add a section to README documenting the workaround: go install + PATH export.","status":"closed","priority":3,"issue_type":"task","created_at":"2025-12-01T21:02:24.511955-08:00","updated_at":"2025-12-01T21:10:10.587639-08:00","closed_at":"2025-12-01T21:10:10.587639-08:00","close_reason":"Added documentation for go install fallback when npm postinstall fails due to network restrictions in Claude Code web environments."}
 {"id":"bd-91x","title":"Fix dependency naming inconsistencies (GH #440)","description":"Parent-child dependency documentation is backwards and UI labels are confusing.\\n\\nProblems:\\n1. DEPENDENCIES.md says 'bd dep add PARENT CHILD' but this is rejected\\n2. bd show displays epic children under 'Blocks' instead of 'Children'\\n3. bd dep tree EPIC shows nothing (need --direction=up)\\n4. Inconsistent with 'bd epic status' which uses 'children'\\n\\nSee: https://github.com/steveyegge/beads/issues/440","status":"closed","priority":2,"issue_type":"bug","created_at":"2025-12-01T21:01:41.63295-08:00","updated_at":"2025-12-01T21:06:17.866688-08:00","closed_at":"2025-12-01T21:06:17.866688-08:00"}
 {"id":"bd-93d","title":"Jira export script (jsonl2jira.py)","description":"Create a Python script to push beads issues to Jira.\n\n**Requires**: Jira import script to be complete first (need external_ref matching logic working)\n\n**Features needed**:\n- Create new Jira issues from beads issues without external_ref\n- Update existing Jira issues matched by external_ref\n- Map beads fields back to Jira fields\n- Handle Jira workflow transitions (status changes may need transitions)\n- Support custom field mapping for design/acceptance_criteria/notes\n\n**Challenges**:\n- Jira status changes often require workflow transitions, not direct updates\n- Need to discover valid transitions via API\n- Custom fields vary by Jira instance\n\n**Usage**:\n```bash\nbd export | python jsonl2jira.py --create-only  # Only create, don't update\nbd export | python jsonl2jira.py                 # Create and update\n```\n\n**After creation**: Sets external_ref on beads issue to link back","status":"closed","priority":2,"issue_type":"feature","created_at":"2025-11-30T12:56:14.266357-08:00","updated_at":"2025-11-30T15:19:40.264737-08:00","closed_at":"2025-11-30T15:19:40.264737-08:00","dependencies":[{"issue_id":"bd-93d","depends_on_id":"bd-qvj","type":"parent-child","created_at":"2025-11-30T12:56:44.652391-08:00","created_by":"stevey"},{"issue_id":"bd-93d","depends_on_id":"bd-tjn","type":"blocks","created_at":"2025-11-30T12:56:54.941116-08:00","created_by":"stevey"}]}
@@ -48,6 +49,7 @@
 {"id":"bd-c8x","title":"Don't search parent directories for .beads databases","description":"bd currently walks up the directory tree looking for .beads directories, which can find unrelated databases (e.g., ~/.beads). This causes confusing warnings and potential data pollution.\n\nShould either:\n1. Stop at git root (don't search above it)\n2. Only use explicit BEADS_DB env var or local .beads\n3. At minimum, don't search in home directory","status":"closed","priority":2,"issue_type":"bug","created_at":"2025-11-27T22:10:41.992686-08:00","updated_at":"2025-11-28T22:17:12.607956-08:00","closed_at":"2025-11-28T22:15:55.878353-08:00"}
 {"id":"bd-clg","title":"bd jira sync command","description":"Add a built-in bd command for Jira synchronization.\n\n**Requires**: Both import and export scripts working\n\n**Features**:\n- `bd jira sync --pull` - Import from Jira to beads\n- `bd jira sync --push` - Export from beads to Jira\n- `bd jira sync` - Bidirectional (pull then push, with conflict resolution)\n- `bd jira status` - Show sync status and last sync time\n\n**Conflict resolution**:\n- Timestamp-based: newer update wins\n- Option for --prefer-local or --prefer-jira to override\n- Interactive mode for manual conflict resolution (optional)\n\n**Integration**:\n- Uses jira.* config settings from bd config\n- Stores last sync timestamp in config\n- Logs sync activity for audit\n\n**Stretch goals**:\n- Webhook integration for real-time sync\n- Selective sync by JQL filter","status":"closed","priority":3,"issue_type":"feature","created_at":"2025-11-30T12:56:27.716537-08:00","updated_at":"2025-11-30T15:25:37.896045-08:00","closed_at":"2025-11-30T15:25:37.896045-08:00","dependencies":[{"issue_id":"bd-clg","depends_on_id":"bd-qvj","type":"parent-child","created_at":"2025-11-30T12:56:49.796568-08:00","created_by":"stevey"},{"issue_id":"bd-clg","depends_on_id":"bd-tjn","type":"blocks","created_at":"2025-11-30T12:57:00.075288-08:00","created_by":"stevey"},{"issue_id":"bd-clg","depends_on_id":"bd-93d","type":"blocks","created_at":"2025-11-30T12:57:05.206431-08:00","created_by":"stevey"}]}
 {"id":"bd-co0","title":"Imperator does not know its own mail identity","description":"","status":"closed","priority":1,"issue_type":"bug","created_at":"2025-11-30T22:53:49.963803-08:00","updated_at":"2025-12-01T22:01:26.953199-08:00","closed_at":"2025-12-01T22:01:26.953199-08:00"}
+{"id":"bd-d0t","title":"Priority 0 in merge may incorrectly win over set priorities","description":"In mergePriority(), priority 0 (which may mean 'unset' due to Go's zero value) beats any explicitly set priority like P1, P2, etc. Should probably treat 0 as 'no priority set' and not let it win conflicts.","status":"open","priority":3,"issue_type":"bug","created_at":"2025-12-02T20:14:58.906543-08:00","updated_at":"2025-12-02T20:14:58.906543-08:00"}
 {"id":"bd-d4i","title":"Create tip system infrastructure for contextual hints","description":"Implement a tip/hint system that shows helpful contextual messages after successful commands. This is different from the existing error-path \"Hint:\" messages - tips appear on success paths to educate users about features they might not know about.","status":"closed","priority":2,"issue_type":"feature","created_at":"2025-11-11T23:29:15.693956-08:00","updated_at":"2025-11-25T17:47:30.747566-08:00","closed_at":"2025-11-25T17:47:30.747566-08:00"}
 {"id":"bd-dmb","title":"Fresh clone: bd should suggest 'bd init' when no database exists","description":"On a fresh clone of a repo using beads, running `bd stats` or `bd list` gives a cryptic error:\n\n```\nError: failed to open database: post-migration validation failed: migration invariants failed:\n  - required_config_present: required config key missing: issue_prefix (database has 2 issues)\n```\n\n**Expected**: A helpful message like:\n```\nNo database found. This appears to be a fresh clone.\nRun 'bd init --prefix \u003cprefix\u003e' to hydrate from the committed JSONL file.\nFound: .beads/beads.jsonl (38 issues)\n```\n\n**Why this matters**: The current UX is confusing for new contributors or fresh clones. The happy path should be obvious.","status":"closed","priority":1,"issue_type":"feature","created_at":"2025-11-27T20:21:04.947959-08:00","updated_at":"2025-11-27T22:40:11.654051-08:00","closed_at":"2025-11-27T22:40:11.654051-08:00"}
 {"id":"bd-e166","title":"Improve timestamp comparison readability in import","description":"The timestamp comparison logic uses double-negative which can be confusing:\n\nCurrent code:\nif !incoming.UpdatedAt.After(existing.UpdatedAt) {\n    // skip update\n}\n\nMore readable:\nif incoming.UpdatedAt.After(existing.UpdatedAt) {\n    // perform update\n} else {\n    // skip (local is newer)\n}\n\nThis is a minor refactor for code clarity.\n\nRelated: bd-1022\nFiles: internal/importer/importer.go:411, 488","status":"closed","priority":4,"issue_type":"chore","created_at":"2025-11-02T15:32:12.27108-08:00","updated_at":"2025-11-26T22:25:27.124071-08:00","closed_at":"2025-11-26T22:25:27.124071-08:00"}

internal/merge/merge.go

@@ -33,8 +33,6 @@ import (
 	"fmt"
 	"os"
 	"time"
-
-	"github.com/google/go-cmp/cmp"
 )
 
 // Issue represents a beads issue with all possible fields
@@ -289,12 +287,14 @@ func merge3Way(base, left, right []Issue) ([]Issue, []string) {
 				result = append(result, merged)
 			}
 		} else if !inBase && inLeft && inRight {
-			// Added in both - check if identical
+			// Added in both - merge using deterministic rules with empty base
-			if issuesEqual(leftIssue, rightIssue) {
+			emptyBase := Issue{
-				result = append(result, leftIssue)
+				ID:        leftIssue.ID,
-			} else {
+				CreatedAt: leftIssue.CreatedAt,
-				conflicts = append(conflicts, makeConflict(leftIssue.RawLine, rightIssue.RawLine))
+				CreatedBy: leftIssue.CreatedBy,
 			}
+			merged, _ := mergeIssue(emptyBase, leftIssue, rightIssue)
+			result = append(result, merged)
 		} else if inBase && inLeft && !inRight {
 			// Deleted in right, maybe modified in left
 			// RULE 2: deletion always wins over modification
@@ -324,31 +324,22 @@ func mergeIssue(base, left, right Issue) (Issue, string) {
 		CreatedBy: base.CreatedBy,
 	}
 
-	// Merge title
+	// Merge title - on conflict, side with latest updated_at wins
-	result.Title = mergeField(base.Title, left.Title, right.Title)
+	result.Title = mergeFieldByUpdatedAt(base.Title, left.Title, right.Title, left.UpdatedAt, right.UpdatedAt)
 
-	// Merge description
+	// Merge description - on conflict, side with latest updated_at wins
-	result.Description = mergeField(base.Description, left.Description, right.Description)
+	result.Description = mergeFieldByUpdatedAt(base.Description, left.Description, right.Description, left.UpdatedAt, right.UpdatedAt)
 
-	// Merge notes
+	// Merge notes - on conflict, concatenate both sides
-	result.Notes = mergeField(base.Notes, left.Notes, right.Notes)
+	result.Notes = mergeNotes(base.Notes, left.Notes, right.Notes)
 
 	// Merge status - SPECIAL RULE: closed always wins over open
 	result.Status = mergeStatus(base.Status, left.Status, right.Status)
 
-	// Merge priority (as int)
+	// Merge priority - on conflict, higher priority wins (lower number = more urgent)
-	if base.Priority == left.Priority && base.Priority != right.Priority {
+	result.Priority = mergePriority(base.Priority, left.Priority, right.Priority)
-		result.Priority = right.Priority
-	} else if base.Priority == right.Priority && base.Priority != left.Priority {
-		result.Priority = left.Priority
-	} else if left.Priority == right.Priority {
-		result.Priority = left.Priority
-	} else {
-		// Conflict - take left for now
-		result.Priority = left.Priority
-	}
 
-	// Merge issue_type
+	// Merge issue_type - on conflict, local (left) wins
 	result.IssueType = mergeField(base.IssueType, left.IssueType, right.IssueType)
 
 	// Merge updated_at - take the max
@@ -365,11 +356,7 @@ func mergeIssue(base, left, right Issue) (Issue, string) {
 	// Merge dependencies - combine and deduplicate
 	result.Dependencies = mergeDependencies(left.Dependencies, right.Dependencies)
 
-	// Check if we have a real conflict
+	// All field conflicts are now auto-resolved deterministically
-	if hasConflict(base, left, right) {
-		return result, makeConflictWithBase(base.RawLine, left.RawLine, right.RawLine)
-	}
-
 	return result, ""
 }
 
@@ -391,10 +378,110 @@ func mergeField(base, left, right string) string {
 	if base == right && base != left {
 		return left
 	}
-	// Both changed to same value or no change
+	// Both changed to same value or no change - left wins
 	return left
 }
 
+// mergeFieldByUpdatedAt resolves conflicts by picking the value from the side
+// with the latest updated_at timestamp
+func mergeFieldByUpdatedAt(base, left, right, leftUpdatedAt, rightUpdatedAt string) string {
+	// Standard 3-way merge for non-conflict cases
+	if base == left && base != right {
+		return right
+	}
+	if base == right && base != left {
+		return left
+	}
+	if left == right {
+		return left
+	}
+	// True conflict: both sides changed to different values
+	// Pick the value from the side with the latest updated_at
+	if isTimeAfter(leftUpdatedAt, rightUpdatedAt) {
+		return left
+	}
+	return right
+}
+
+// mergeNotes handles notes merging - on conflict, concatenate both sides
+func mergeNotes(base, left, right string) string {
+	// Standard 3-way merge for non-conflict cases
+	if base == left && base != right {
+		return right
+	}
+	if base == right && base != left {
+		return left
+	}
+	if left == right {
+		return left
+	}
+	// True conflict: both sides changed to different values - concatenate
+	if left == "" {
+		return right
+	}
+	if right == "" {
+		return left
+	}
+	return left + "\n\n---\n\n" + right
+}
+
+// mergePriority handles priority merging - on conflict, higher priority wins (lower number)
+func mergePriority(base, left, right int) int {
+	// Standard 3-way merge for non-conflict cases
+	if base == left && base != right {
+		return right
+	}
+	if base == right && base != left {
+		return left
+	}
+	if left == right {
+		return left
+	}
+	// True conflict: both sides changed to different values
+	// Higher priority wins (lower number = more urgent)
+	if left < right {
+		return left
+	}
+	return right
+}
+
+// isTimeAfter returns true if t1 is after t2
+func isTimeAfter(t1, t2 string) bool {
+	if t1 == "" {
+		return false
+	}
+	if t2 == "" {
+		return true
+	}
+
+	time1, err1 := time.Parse(time.RFC3339Nano, t1)
+	if err1 != nil {
+		time1, err1 = time.Parse(time.RFC3339, t1)
+	}
+
+	time2, err2 := time.Parse(time.RFC3339Nano, t2)
+	if err2 != nil {
+		time2, err2 = time.Parse(time.RFC3339, t2)
+	}
+
+	// Handle parse errors consistently with maxTime:
+	// - Valid timestamp beats invalid
+	// - If both invalid, prefer left (t1) for consistency
+	if err1 != nil && err2 != nil {
+		return true // both invalid, prefer left
+	}
+	if err1 != nil {
+		return false // t1 invalid, t2 valid - t2 wins
+	}
+	if err2 != nil {
+		return true // t1 valid, t2 invalid - t1 wins
+	}
+
+	// Both valid - compare. On exact tie, return false (right wins for now)
+	// TODO: Consider preferring left on tie for consistency with IssueType rule
+	return time1.After(time2)
+}
+
 func maxTime(t1, t2 string) string {
 	if t1 == "" && t2 == "" {
 		return ""
@@ -459,62 +546,3 @@ func mergeDependencies(left, right []Dependency) []Dependency {
 	return result
 }
 
-func hasConflict(base, left, right Issue) bool {
-	// Check if any field has conflicting changes
-	if base.Title != left.Title && base.Title != right.Title && left.Title != right.Title {
-		return true
-	}
-	if base.Description != left.Description && base.Description != right.Description && left.Description != right.Description {
-		return true
-	}
-	if base.Notes != left.Notes && base.Notes != right.Notes && left.Notes != right.Notes {
-		return true
-	}
-	if base.Status != left.Status && base.Status != right.Status && left.Status != right.Status {
-		return true
-	}
-	if base.Priority != left.Priority && base.Priority != right.Priority && left.Priority != right.Priority {
-		return true
-	}
-	if base.IssueType != left.IssueType && base.IssueType != right.IssueType && left.IssueType != right.IssueType {
-		return true
-	}
-	return false
-}
-
-func issuesEqual(a, b Issue) bool {
-	// Use go-cmp for deep equality comparison, ignoring RawLine field
-	return cmp.Equal(a, b, cmp.FilterPath(func(p cmp.Path) bool {
-		return p.String() == "RawLine"
-	}, cmp.Ignore()))
-}
-
-func makeConflict(left, right string) string {
-	conflict := "<<<<<<< left\n"
-	if left != "" {
-		conflict += left + "\n"
-	}
-	conflict += "=======\n"
-	if right != "" {
-		conflict += right + "\n"
-	}
-	conflict += ">>>>>>> right\n"
-	return conflict
-}
-
-func makeConflictWithBase(base, left, right string) string {
-	conflict := "<<<<<<< left\n"
-	if left != "" {
-		conflict += left + "\n"
-	}
-	conflict += "||||||| base\n"
-	if base != "" {
-		conflict += base + "\n"
-	}
-	conflict += "=======\n"
-	if right != "" {
-		conflict += right + "\n"
-	}
-	conflict += ">>>>>>> right\n"
-	return conflict
-}

internal/merge/merge_test.go

@@ -298,6 +298,80 @@ func TestMaxTime(t *testing.T) {
 	}
 }
 
+// TestIsTimeAfter tests timestamp comparison including error handling
+func TestIsTimeAfter(t *testing.T) {
+	tests := []struct {
+		name     string
+		t1       string
+		t2       string
+		expected bool
+	}{
+		{
+			name:     "both empty - prefer left",
+			t1:       "",
+			t2:       "",
+			expected: false,
+		},
+		{
+			name:     "t1 empty - t2 wins",
+			t1:       "",
+			t2:       "2024-01-02T00:00:00Z",
+			expected: false,
+		},
+		{
+			name:     "t2 empty - t1 wins",
+			t1:       "2024-01-01T00:00:00Z",
+			t2:       "",
+			expected: true,
+		},
+		{
+			name:     "t1 newer",
+			t1:       "2024-01-02T00:00:00Z",
+			t2:       "2024-01-01T00:00:00Z",
+			expected: true,
+		},
+		{
+			name:     "t2 newer",
+			t1:       "2024-01-01T00:00:00Z",
+			t2:       "2024-01-02T00:00:00Z",
+			expected: false,
+		},
+		{
+			name:     "identical timestamps - right wins (false)",
+			t1:       "2024-01-01T00:00:00Z",
+			t2:       "2024-01-01T00:00:00Z",
+			expected: false,
+		},
+		{
+			name:     "t1 invalid, t2 valid - t2 wins",
+			t1:       "not-a-timestamp",
+			t2:       "2024-01-01T00:00:00Z",
+			expected: false,
+		},
+		{
+			name:     "t1 valid, t2 invalid - t1 wins",
+			t1:       "2024-01-01T00:00:00Z",
+			t2:       "not-a-timestamp",
+			expected: true,
+		},
+		{
+			name:     "both invalid - prefer left",
+			t1:       "invalid1",
+			t2:       "invalid2",
+			expected: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isTimeAfter(tt.t1, tt.t2)
+			if result != tt.expected {
+				t.Errorf("isTimeAfter(%q, %q) = %v, want %v", tt.t1, tt.t2, result, tt.expected)
+			}
+		})
+	}
+}
+
 // TestMerge3Way_SimpleUpdates tests simple field update scenarios
 func TestMerge3Way_SimpleUpdates(t *testing.T) {
 	base := []Issue{
@@ -409,52 +483,54 @@ func TestMerge3Way_SimpleUpdates(t *testing.T) {
 	})
 }
 
-// TestMerge3Way_Conflicts tests conflict detection
+// TestMerge3Way_AutoResolve tests auto-resolution of conflicts
-func TestMerge3Way_Conflicts(t *testing.T) {
+func TestMerge3Way_AutoResolve(t *testing.T) {
-	t.Run("conflicting title changes", func(t *testing.T) {
+	t.Run("conflicting title changes - latest updated_at wins", func(t *testing.T) {
 		base := []Issue{
 			{
 				ID:        "bd-abc123",
 				Title:     "Original",
+				UpdatedAt: "2024-01-01T00:00:00Z",
 				CreatedAt: "2024-01-01T00:00:00Z",
 				CreatedBy: "user1",
-				RawLine:   `{"id":"bd-abc123","title":"Original","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+				RawLine:   `{"id":"bd-abc123","title":"Original","updated_at":"2024-01-01T00:00:00Z","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
 			},
 		}
 		left := []Issue{
 			{
 				ID:        "bd-abc123",
 				Title:     "Left version",
+				UpdatedAt: "2024-01-02T00:00:00Z", // Older
 				CreatedAt: "2024-01-01T00:00:00Z",
 				CreatedBy: "user1",
-				RawLine:   `{"id":"bd-abc123","title":"Left version","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+				RawLine:   `{"id":"bd-abc123","title":"Left version","updated_at":"2024-01-02T00:00:00Z","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
 			},
 		}
 		right := []Issue{
 			{
 				ID:        "bd-abc123",
 				Title:     "Right version",
+				UpdatedAt: "2024-01-03T00:00:00Z", // Newer - this should win
 				CreatedAt: "2024-01-01T00:00:00Z",
 				CreatedBy: "user1",
-				RawLine:   `{"id":"bd-abc123","title":"Right version","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+				RawLine:   `{"id":"bd-abc123","title":"Right version","updated_at":"2024-01-03T00:00:00Z","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
 			},
 		}
 
 		result, conflicts := merge3Way(base, left, right)
-		if len(conflicts) == 0 {
+		if len(conflicts) != 0 {
-			t.Error("expected conflict for divergent title changes")
+			t.Errorf("expected no conflicts with auto-resolution, got %d", len(conflicts))
 		}
-		if len(result) != 0 {
+		if len(result) != 1 {
-			t.Errorf("expected no merged issues with conflict, got %d", len(result))
+			t.Fatalf("expected 1 merged issue, got %d", len(result))
 		}
-		if len(conflicts) > 0 {
+		// Right has newer updated_at, so right's title wins
-			if conflicts[0] == "" {
+		if result[0].Title != "Right version" {
-				t.Error("conflict marker should not be empty")
+			t.Errorf("expected title 'Right version' (newer updated_at), got %q", result[0].Title)
-			}
 		}
 	})
 
-	t.Run("conflicting priority changes", func(t *testing.T) {
+	t.Run("conflicting priority changes - higher priority wins (lower number)", func(t *testing.T) {
 		base := []Issue{
 			{
 				ID:        "bd-abc123",
@@ -467,16 +543,16 @@ func TestMerge3Way_Conflicts(t *testing.T) {
 		left := []Issue{
 			{
 				ID:        "bd-abc123",
-				Priority:  0,
+				Priority:  3, // Lower priority (higher number)
 				CreatedAt: "2024-01-01T00:00:00Z",
 				CreatedBy: "user1",
-				RawLine:   `{"id":"bd-abc123","priority":0,"created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+				RawLine:   `{"id":"bd-abc123","priority":3,"created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
 			},
 		}
 		right := []Issue{
 			{
 				ID:        "bd-abc123",
-				Priority:  1,
+				Priority:  1, // Higher priority (lower number) - this should win
 				CreatedAt: "2024-01-01T00:00:00Z",
 				CreatedBy: "user1",
 				RawLine:   `{"id":"bd-abc123","priority":1,"created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
@@ -484,11 +560,100 @@ func TestMerge3Way_Conflicts(t *testing.T) {
 		}
 
 		result, conflicts := merge3Way(base, left, right)
-		if len(conflicts) == 0 {
+		if len(conflicts) != 0 {
-			t.Error("expected conflict for divergent priority changes")
+			t.Errorf("expected no conflicts with auto-resolution, got %d", len(conflicts))
 		}
-		if len(result) != 0 {
+		if len(result) != 1 {
-			t.Errorf("expected no merged issues with conflict, got %d", len(result))
+			t.Fatalf("expected 1 merged issue, got %d", len(result))
+		}
+		// Lower priority number wins
+		if result[0].Priority != 1 {
+			t.Errorf("expected priority 1 (higher priority), got %d", result[0].Priority)
+		}
+	})
+
+	t.Run("conflicting notes - concatenated", func(t *testing.T) {
+		base := []Issue{
+			{
+				ID:        "bd-abc123",
+				Notes:     "Original notes",
+				CreatedAt: "2024-01-01T00:00:00Z",
+				CreatedBy: "user1",
+				RawLine:   `{"id":"bd-abc123","notes":"Original notes","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+			},
+		}
+		left := []Issue{
+			{
+				ID:        "bd-abc123",
+				Notes:     "Left notes",
+				CreatedAt: "2024-01-01T00:00:00Z",
+				CreatedBy: "user1",
+				RawLine:   `{"id":"bd-abc123","notes":"Left notes","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+			},
+		}
+		right := []Issue{
+			{
+				ID:        "bd-abc123",
+				Notes:     "Right notes",
+				CreatedAt: "2024-01-01T00:00:00Z",
+				CreatedBy: "user1",
+				RawLine:   `{"id":"bd-abc123","notes":"Right notes","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+			},
+		}
+
+		result, conflicts := merge3Way(base, left, right)
+		if len(conflicts) != 0 {
+			t.Errorf("expected no conflicts with auto-resolution, got %d", len(conflicts))
+		}
+		if len(result) != 1 {
+			t.Fatalf("expected 1 merged issue, got %d", len(result))
+		}
+		// Notes should be concatenated
+		expectedNotes := "Left notes\n\n---\n\nRight notes"
+		if result[0].Notes != expectedNotes {
+			t.Errorf("expected notes %q, got %q", expectedNotes, result[0].Notes)
+		}
+	})
+
+	t.Run("conflicting issue_type - local (left) wins", func(t *testing.T) {
+		base := []Issue{
+			{
+				ID:        "bd-abc123",
+				IssueType: "task",
+				CreatedAt: "2024-01-01T00:00:00Z",
+				CreatedBy: "user1",
+				RawLine:   `{"id":"bd-abc123","issue_type":"task","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+			},
+		}
+		left := []Issue{
+			{
+				ID:        "bd-abc123",
+				IssueType: "bug", // Local change - should win
+				CreatedAt: "2024-01-01T00:00:00Z",
+				CreatedBy: "user1",
+				RawLine:   `{"id":"bd-abc123","issue_type":"bug","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+			},
+		}
+		right := []Issue{
+			{
+				ID:        "bd-abc123",
+				IssueType: "feature",
+				CreatedAt: "2024-01-01T00:00:00Z",
+				CreatedBy: "user1",
+				RawLine:   `{"id":"bd-abc123","issue_type":"feature","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+			},
+		}
+
+		result, conflicts := merge3Way(base, left, right)
+		if len(conflicts) != 0 {
+			t.Errorf("expected no conflicts with auto-resolution, got %d", len(conflicts))
+		}
+		if len(result) != 1 {
+			t.Fatalf("expected 1 merged issue, got %d", len(result))
+		}
+		// Local (left) wins for issue_type
+		if result[0].IssueType != "bug" {
+			t.Errorf("expected issue_type 'bug' (local wins), got %q", result[0].IssueType)
 		}
 	})
 }
@@ -679,33 +844,39 @@ func TestMerge3Way_Additions(t *testing.T) {
 		}
 	})
 
-	t.Run("added in both with different content - conflict", func(t *testing.T) {
+	t.Run("added in both with different content - auto-resolved", func(t *testing.T) {
 		base := []Issue{}
 		left := []Issue{
 			{
 				ID:        "bd-abc123",
 				Title:     "Left version",
+				UpdatedAt: "2024-01-02T00:00:00Z", // Older
 				CreatedAt: "2024-01-01T00:00:00Z",
 				CreatedBy: "user1",
-				RawLine:   `{"id":"bd-abc123","title":"Left version","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+				RawLine:   `{"id":"bd-abc123","title":"Left version","updated_at":"2024-01-02T00:00:00Z","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
 			},
 		}
 		right := []Issue{
 			{
 				ID:        "bd-abc123",
 				Title:     "Right version",
+				UpdatedAt: "2024-01-03T00:00:00Z", // Newer - should win
 				CreatedAt: "2024-01-01T00:00:00Z",
 				CreatedBy: "user1",
-				RawLine:   `{"id":"bd-abc123","title":"Right version","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
+				RawLine:   `{"id":"bd-abc123","title":"Right version","updated_at":"2024-01-03T00:00:00Z","created_at":"2024-01-01T00:00:00Z","created_by":"user1"}`,
 			},
 		}
 
 		result, conflicts := merge3Way(base, left, right)
-		if len(conflicts) == 0 {
+		if len(conflicts) != 0 {
-			t.Error("expected conflict for different additions")
+			t.Errorf("expected no conflicts with auto-resolution, got %d", len(conflicts))
 		}
-		if len(result) != 0 {
+		if len(result) != 1 {
-			t.Errorf("expected no merged issues with conflict, got %d", len(result))
+			t.Fatalf("expected 1 merged issue, got %d", len(result))
+		}
+		// Right has newer updated_at, so right's title wins
+		if result[0].Title != "Right version" {
+			t.Errorf("expected title 'Right version' (newer updated_at), got %q", result[0].Title)
 		}
 	})
 }