fix: gt commands follow .beads/redirect for shared beads (gt-ln5af)

Added ResolveBeadsDir() helper that follows .beads/redirect files,
enabling crew workers and polecats to properly access shared beads.

Updated callers:
- mailbox.go: NewMailboxFromAddress follows redirect
- catalog.go: LoadCatalog follows redirect at all levels
- doctor checks: beads_check, patrol_check, wisp_check follow redirect

Also added comprehensive tests for the redirect resolution logic.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/doctor/patrol_check.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/steveyegge/gastown/internal/beads"
 	"github.com/steveyegge/gastown/internal/config"
 )
 
@@ -262,7 +263,10 @@ func (c *PatrolNotStuckCheck) Run(ctx *CheckContext) *CheckResult {
 	var stuckWisps []string
 	for _, rigName := range rigs {
 		// Check main beads database for wisps (issues with Wisp=true)
-		beadsPath := filepath.Join(ctx.TownRoot, rigName, ".beads", "issues.jsonl")
+		// Follows redirect if present (rig root may redirect to mayor/rig/.beads)
+		rigPath := filepath.Join(ctx.TownRoot, rigName)
+		beadsDir := beads.ResolveBeadsDir(rigPath)
+		beadsPath := filepath.Join(beadsDir, "issues.jsonl")
 		stuck := c.checkStuckWisps(beadsPath, rigName)
 		stuckWisps = append(stuckWisps, stuck...)
 	}