feat: Add bd repos multi-repo commands and fix bd ready for in_progress issues

- Add 'bd repos' command for multi-repository management (bd-123)
  - bd repos list: show all cached repositories
  - bd repos ready: aggregate ready work across repos
  - bd repos stats: combined statistics across repos
  - bd repos clear-cache: clear repository cache
  - Requires global daemon (bd daemon --global)

- Fix bd ready to show in_progress issues (bd-165)
  - bd ready now shows both 'open' and 'in_progress' issues with no blockers
  - Allows epics/tasks ready to close to appear in ready work
  - Critical P0 bug fix for workflow

- Apply code review improvements to repos implementation
  - Use strongly typed RPC responses (remove interface{})
  - Fix clear-cache lock handling (close connections outside lock)
  - Add error collection for per-repo failures
  - Add context timeouts (1-2s) to prevent hangs
  - Add lock strategy comments

- Update documentation (README.md, AGENTS.md)
- Add comprehensive tests for both features

Amp-Thread-ID: https://ampcode.com/threads/T-1de989a1-1890-492c-9847-a34144259e0f
Co-authored-by: Amp <amp@ampcode.com>

internal/rpc/protocol.go

@@ -1,23 +1,31 @@
 package rpc
 
-import "encoding/json"
+import (
+	"encoding/json"
+
+	"github.com/steveyegge/beads/internal/types"
+)
 
 // Operation constants for all bd commands
 const (
-	OpPing        = "ping"
-	OpCreate      = "create"
-	OpUpdate      = "update"
-	OpClose       = "close"
-	OpList        = "list"
-	OpShow        = "show"
-	OpReady       = "ready"
-	OpStats       = "stats"
-	OpDepAdd      = "dep_add"
-	OpDepRemove   = "dep_remove"
-	OpDepTree     = "dep_tree"
-	OpLabelAdd    = "label_add"
-	OpLabelRemove = "label_remove"
-	OpBatch       = "batch"
+	OpPing           = "ping"
+	OpCreate         = "create"
+	OpUpdate         = "update"
+	OpClose          = "close"
+	OpList           = "list"
+	OpShow           = "show"
+	OpReady          = "ready"
+	OpStats          = "stats"
+	OpDepAdd         = "dep_add"
+	OpDepRemove      = "dep_remove"
+	OpDepTree        = "dep_tree"
+	OpLabelAdd       = "label_add"
+	OpLabelRemove    = "label_remove"
+	OpBatch          = "batch"
+	OpReposList      = "repos_list"
+	OpReposReady     = "repos_ready"
+	OpReposStats     = "repos_stats"
+	OpReposClearCache = "repos_clear_cache"
 )
 
 // Request represents an RPC request from client to daemon
@@ -151,3 +159,38 @@ type BatchResult struct {
 	Data    json.RawMessage `json:"data,omitempty"`
 	Error   string          `json:"error,omitempty"`
 }
+
+// ReposReadyArgs represents arguments for repos ready operation
+type ReposReadyArgs struct {
+	Assignee    string `json:"assignee,omitempty"`
+	Priority    *int   `json:"priority,omitempty"`
+	Limit       int    `json:"limit,omitempty"`
+	GroupByRepo bool   `json:"group_by_repo,omitempty"`
+}
+
+// RepoInfo represents information about a cached repository
+type RepoInfo struct {
+	Path       string `json:"path"`
+	Prefix     string `json:"prefix"`
+	IssueCount int    `json:"issue_count"`
+	LastAccess string `json:"last_access"`
+}
+
+// RepoReadyWork represents ready work for a single repository
+type RepoReadyWork struct {
+	RepoPath string `json:"repo_path"`
+	Issues   []*types.Issue `json:"issues"`
+}
+
+// ReposReadyIssue represents an issue with repo context
+type ReposReadyIssue struct {
+	RepoPath string       `json:"repo_path"`
+	Issue    *types.Issue `json:"issue"`
+}
+
+// ReposStatsResponse contains combined statistics across repos
+type ReposStatsResponse struct {
+	Total   types.Statistics            `json:"total"`
+	PerRepo map[string]types.Statistics `json:"per_repo"`
+	Errors  map[string]string           `json:"errors,omitempty"`
+}