Investigate jujutsu VCS as potential solution for conflict-free merging

## Context
Current N-way collision resolution struggles with Git line-based merge model. When 5+ clones create issues with same ID, Git merge conflicts require manual resolution, and our collision resolver can fail during convergence rounds.

## Research Question
Could jujutsu (jj) provide better conflict handling for JSONL files?

## Jujutsu Overview
- Next-gen VCS built on libgit2
- Designed to handle conflicts as first-class citizens
- Supports conflict-free replicated data types (CRDTs) in some scenarios
- Better handling of concurrent edits
- Can work with Git repos (compatible with existing infrastructure)

## Investigation Tasks
1. JSONL Merge Behavior - How does jj handle line-by-line JSONL conflicts?
2. Integration Feasibility - Can beads use jj as backend while maintaining Git compatibility?
3. Conflict Resolution Model - Does jj conflict model map to our collision resolution?
4. Operational Transform Support - Does jj implement operational transforms?

## Deliverables
1. Technical report on jj merge algorithm for JSONL
2. Proof-of-concept: 5-clone collision test using jj instead of Git
3. Performance comparison: Git vs jj for beads workload
4. Recommendation: Adopt, experiment further, or abandon

## References
- https://github.com/martinvonz/jj
- Related to bd-e6d71828, bd-7a2b58fc


Split test suites: fast vs. integration

Reorganize tests into separate packages/files for fast unit tests vs slow integration tests.

Benefits:
- Clear separation of concerns
- Easier to run just fast tests during development
- Can parallelize CI jobs better

Files to organize:
- beads_hash_multiclone_test.go (slow integration tests)
- beads_integration_test.go (medium-speed integration tests)
- Other test files (fast unit tests)


Fix N-way collision convergence

Epic to fix the N-way collision convergence problem documented in n-way-collision-convergence.md.

## Problem Summary
The current collision resolution implementation works correctly for 2-way collisions but does not converge for 3-way (and by extension N-way) collisions. TestThreeCloneCollision demonstrates this with reproducible failures.

## Root Causes Identified
1. Pairwise resolution doesn't scale - each clone makes local decisions without global context
2. DetectCollisions modifies state during detection (line 83-86 in collision.go)
3. No remapping history - can't track transitive remap chains (test-1 → test-2 → test-3)
4. Import-time resolution is too late - happens after git merge

## Solution Architecture
Replace pairwise resolution with deterministic global N-way resolution using:
- Content-addressable identity (content hashing)
- Global collision resolution (sort all versions by hash)
- Read-only detection phase (separate from modification)
- Idempotent imports (content-first matching)

## Success Criteria
- TestThreeCloneCollision passes without skipping
- All clones converge to identical content after final pull
- No data loss (all issues present in all clones)
- Works for N workers (test with 5+ clones)
- Idempotent imports (importing same JSONL multiple times is safe)

## Implementation Phases
See child issues for detailed breakdown of each phase.


Update git hooks to be sync.branch aware

## Problem

The 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.

## Current Behavior

1. User configures sync.branch=beads-sync
2. bd sync commits changes to beads-sync via worktree
3. Local .beads/issues.jsonl is updated (needed for import)
4. git push to main triggers pre-push hook
5. Hook sees uncommitted .beads changes and blocks push
6. User must use --no-verify to push

## Expected Behavior

When sync.branch is configured, the pre-push hook should:
1. Check if sync.branch is set (bd config get sync.branch)
2. If set, skip the .beads uncommitted check OR
3. Verify changes are committed to the sync branch instead

## Affected Files

- examples/git-hooks/pre-push
- examples/git-hooks/pre-commit (may also need update)

## Workaround

Use git push --no-verify


Implement bd stale command to find abandoned/forgotten issues

Add bd stale command to surface issues that haven't been updated recently and may need attention.

Use cases:
- In-progress issues with no recent activity (may be abandoned)
- Open issues that have been forgotten
- Issues that might be outdated or no longer relevant

Query logic should find non-closed issues where updated_at exceeds a time threshold.

Should support:
- --days N flag (default 30-90 days)
- --status filter (e.g., only in_progress)
- --json output for automation

References GitHub issue #184 where user expected this command to exist.


Add close_reason field to CLI schema and documentation

PR #551 persists close_reason, but the CLI documentation may not mention this field as part of the issue schema.

## Current State
- close_reason is now persisted in database
- `bd show --json` will return close_reason in JSON output
- Documentation may not reflect this new field

## What's Missing
- CLI reference documentation for close_reason field
- Schema documentation showing close_reason is a top-level issue field
- Example output showing close_reason in bd show --json
- bd close command documentation should mention close_reason parameter is optional

## Suggested Action
1. Update README.md or CLI reference docs to list close_reason as an issue field
2. Add example to bd close documentation
3. Update any type definitions or schema specs
4. Consider adding close_reason to verbose list output (bd list --verbose)


Consolidate ID generation and validation into ids.go

Extract ID logic into ids.go: ValidateIssueIDPrefix, GenerateIssueID, EnsureIDs. Move GetAdaptiveIDLength here. Unify single and bulk ID generation flows.


GH#497: bd onboard copilot-instructions.md is beads-specific, not generic

bd onboard outputs beads repo specific content (Go/SQLite/Cobra) for copilot-instructions.md instead of a generic template. AGENTS.md output is correct. See: https://github.com/steveyegge/beads/issues/497


Add MCP server functions for repair commands

Expose new repair commands via MCP server for agent access:

Functions to add:
- beads_repair_deps()
- beads_detect_pollution()
- beads_validate()
- beads_resolve_conflicts() (when implemented)

Update integrations/beads-mcp/src/beads_mcp/server.py

See repair_commands.md lines 803-884 for design.

Implemented all three MCP server functions:

1. **repair_deps(fix=False)** - Find/fix orphaned dependencies
2. **detect_pollution(clean=False)** - Detect/clean test issues
3. **validate(checks=None, fix_all=False)** - Run comprehensive health checks

Changes:
- Added abstract methods to BdClientBase
- Implemented in BdCliClient (CLI execution)
- Added NotImplementedError stubs in BdDaemonClient (falls back to CLI)
- Created wrapper functions in tools.py
- Registered @mcp.tool decorators in server.py

All commands tested and working with --no-daemon flag.


Add content-addressable identity to Issue type

## Overview
Phase 1: Add content hashing to enable global identification of issues regardless of their assigned IDs.

## Current Problem
The system identifies issues only by ID (e.g., test-1, test-2). When multiple clones create the same ID with different content, there's no way to identify that these are semantically different issues without comparing all fields.

## Solution
Add a ContentHash field to the Issue type that represents the canonical content fingerprint.

## Implementation Tasks

### 1. Add ContentHash field to Issue type
File: internal/types/types.go
```go
type Issue struct {
    ID          string
    ContentHash string  // SHA256 of canonical content
    // ... existing fields
}
```

### 2. Add content hash computation method
Use existing hashIssueContent from collision.go:186 as foundation:
```go
func (i *Issue) ComputeContentHash() string {
    return hashIssueContent(i)
}
```

### 3. Compute hash at creation time
- Modify CreateIssue to compute and store ContentHash
- Modify CreateIssues (batch) to compute hashes

### 4. Compute hash at import time
- Modify ImportIssues to compute ContentHash for all incoming issues
- Store hash in database

### 5. Add database column
- Add migration to add content_hash column to issues table
- Update SELECT/INSERT statements to include content_hash
- Index on content_hash for fast lookups

### 6. Populate existing issues
- Add migration step to compute ContentHash for all existing issues
- Use hashIssueContent function

## Acceptance Criteria
- Issue type has ContentHash field
- Hash is computed automatically at creation time
- Hash is computed for imported issues
- Database stores content_hash column
- All existing issues have non-empty ContentHash
- Hash is deterministic (same content → same hash)
- Hash excludes ID, timestamps (only semantic content)

## Files to Modify
- internal/types/types.go
- internal/storage/sqlite/sqlite.go (schema, CreateIssue, CreateIssues)
- internal/storage/sqlite/migrations.go (new migration)
- internal/importer/importer.go (compute hash during import)
- cmd/bd/create.go (compute hash at creation)

## Testing
- Unit test: same content produces same hash
- Unit test: different content produces different hash
- Unit test: hash excludes ID and timestamps
- Integration test: hash persists in database
- Migration test: existing issues get hashes populated


Implement fs bridge layer for WASM (Go syscall/js to Node.js fs)

Go's os package in WASM returns 'not implemented on js' for mkdir and other file operations. Need to create a bridge layer that:

1. Detects WASM environment (GOOS=js)
2. Uses syscall/js to call Node.js fs module functions
3. Implements wrappers for:
   - os.MkdirAll
   - os.ReadFile / os.WriteFile
   - os.Open / os.Create
   - os.Stat / os.Lstat
   - filepath operations

Approach:
- Create internal/wasm/fs_bridge.go with //go:build js && wasm
- Export Node.js fs functions to Go using global.readFileSync, global.writeFileSync, etc.
- Wrap in Go API that matches os package signatures
- Update beads.go and storage layer to use bridge when in WASM

This unblocks bd-4462 (basic WASM testing) and [deleted:bd-5bbf] (feature parity testing).


Run final validation and cleanup checks

Final validation pass to ensure all cleanup objectives met and no regressions introduced.

Validation checklist:
1. Dead code verification: `go run golang.org/x/tools/cmd/deadcode@latest -test ./...`
2. Test coverage: `go test -cover ./...`
3. Build verification: `go build ./cmd/bd/`
4. Linting: `golangci-lint run`
5. Integration tests
6. Metrics verification
7. Git clean check

Final metrics to report:
- LOC removed: ~____
- Files deleted: ____
- Files created: ____
- Test coverage: ____%
- Build time: ____ (before/after)
- Test run time: ____ (before/after)

Impact: Confirms all cleanup objectives achieved successfully

## Validation Results

**Dead Code:** ✅ Found and removed 1 unreachable function (`DroppedEventsCount`)
**Tests:** ✅ All pass
**Coverage:**
- Main: 39.6%
- cmd/bd: 20.2%
- Created follow-up issues (bd-85487065 through bd-bc2c6191) to improve coverage

**Build:** ✅ Clean
**Linting:** 73 issues (up from 34 baseline)
- Increase due to unused functions from refactoring
- Need cleanup in separate issue

**Integration Tests:** ✅ All pass
**Metrics:** 56,464 LOC across 193 Go files
**Git:** 2 files modified (deadcode fix + auto-synced JSONL)

## Follow-up Issues Created
- bd-85487065: Add tests for internal/autoimport (0% coverage)
- bd-0dcea000: Add tests for internal/importer (0% coverage)
- bd-4d7fca8a: Add tests for internal/utils (0% coverage)
- bd-6221bdcd: Improve cmd/bd coverage (20.2% -> target higher)
- bd-bc2c6191: Improve internal/daemon coverage (22.5% -> target higher)


Fix remaining FK constraint failures in AddComment and ApplyCompaction

Follow-up to PR #348 (Fix FOREIGN KEY constraint failed).

The initial fix addressed CloseIssue, UpdateIssueID, and RemoveLabel.
However, `AddComment` (in internal/storage/sqlite/events.go) and `ApplyCompaction` (in internal/storage/sqlite/compact.go) still suffer from the same pattern: inserting an event after an UPDATE without verifying the UPDATE affected any rows.

This causes "FOREIGN KEY constraint failed" errors when operating on non-existent issues, instead of clean "issue not found" errors.

Task:
1. Apply the same fix pattern to `AddComment` and `ApplyCompaction`: check RowsAffected() after UPDATE and before event INSERT.
2. Ensure error messages are consistent ("issue %s not found").
3. Verify with reproduction tests (create a test that calls these methods with a non-existent ID).


Prevent multiple daemons from running on the same repo

Multiple bd daemons running on the same repo clone causes race conditions and data corruption risks.

**Problem:**
- Nothing prevents spawning multiple daemons for the same repository
- Multiple daemons watching the same files can conflict during sync operations
- Observed: 4 daemons running simultaneously caused sync race condition

**Solution:**
Implement daemon singleton enforcement per repo:
1. Use a lock file (e.g., .beads/.daemon.lock) with PID
2. On daemon start, check if lock exists and process is alive
3. If stale lock (dead PID), clean up and acquire lock
4. If active daemon exists, either:
   - Exit with message 'daemon already running (PID xxx)'
   - Or offer --replace flag to kill existing and take over
5. Release lock on graceful shutdown

**Edge cases to handle:**
- Daemon crashes without releasing lock (stale PID detection)
- Multiple repos in same directory tree (each repo gets own lock)
- Race between two daemons starting simultaneously (atomic lock acquisition)


bd-hv01: Missing cleanup of .merged temp file on failure

Problem: deletion_tracking.go:49 creates tmpMerged file but does not clean up on failure, causing disk space leak and potential interference with subsequent syncs.

Fix: Add defer os.Remove(tmpMerged) after creating temp file path.

Files: cmd/bd/deletion_tracking.go:38-89


Fix GH #227: bd edit broken pipe errors

bd edit command gets "broken pipe" errors when using daemon mode because editing can take minutes and the daemon connection times out.

Solution: Force bd edit to always use direct mode (--no-daemon) since it's human-only and interactive.

Fixed by checking cmd.Name() == "edit" in main.go PersistentPreRun and setting noDaemon = true.


Create Python adapter library

Create beads_mail_adapter.py library that wraps Agent Mail HTTP calls with health checks and graceful degradation.

Acceptance Criteria:
- AgentMailAdapter class with health check on init
- enabled flag auto-disables if server unreachable
- All methods wrapped in try/catch (non-blocking failures)
- Methods: reserve_issue(), release_issue(), notify(), check_inbox()
- Environment-based configuration (AGENT_MAIL_URL, AGENT_MAIL_TOKEN)
- Unit tests for enabled/disabled modes

File: lib/beads_mail_adapter.py


Document sandbox workarounds for GH #353

Add documentation for sandbox troubleshooting and new flags.

**Tasks:**
1. Create or update TROUBLESHOOTING.md with sandbox section
2. Document new flags in CLI reference
3. Add comment to GH #353 with immediate workarounds

**Content needed:**
- Symptoms of daemon lock issues in sandboxed environments
- Usage guide for --sandbox, --force, and --allow-stale flags
- Step-by-step troubleshooting for Codex users
- Examples of each escape hatch

**Files to update:**
- docs/TROUBLESHOOTING.md (create if needed)
- docs/CLI_REFERENCE.md or README.md
- GitHub issue #353

**References:**
- docs/GH353_INVESTIGATION.md (lines 240-276)


Daemon performAutoImport should update jsonl_content_hash after import

The daemon's performAutoImport function was not updating jsonl_content_hash after successful import, unlike the CLI import path. This could cause repeated imports if the file hash and DB hash diverge.

Fix: Added hash update after validatePostImport succeeds, using repoKey for multi-repo support.