fix(routing): handle symlinked .beads directories correctly (#1112)

When .beads is a symlink (e.g., ~/gt/.beads -> ~/gt/olympus/.beads),
findTownRoutes() incorrectly used filepath.Dir() on the resolved
symlink path to determine the town root.

This caused route resolution to fail because the town root would be
~/gt/olympus instead of ~/gt, making routes point to non-existent
directories.

The fix adds findTownRootFromCWD() which walks up from the current
working directory instead of the beads directory path. This finds
the correct town root regardless of symlink resolution.

Changes:
- Add findTownRootFromCWD() function
- Update findTownRoutes() to use CWD-based town root detection
- Add fallback to filepath.Dir() for non-Gas Town repos
- Add debug logging (BD_DEBUG_ROUTING=1)
- Add comprehensive test case

Test: go test ./internal/routing/...

internal/routing/routes.go

@@ -291,20 +291,52 @@ func findTownRoot(startDir string) string {
 	}
 }
 
+// findTownRootFromCWD walks up from the current working directory looking for a town root.
+// This is used to handle symlinked .beads directories correctly.
+// By starting from CWD instead of the beads directory path, we find the correct
+// town root even when .beads is a symlink that points elsewhere.
+func findTownRootFromCWD() string {
+	cwd, err := os.Getwd()
+	if err != nil {
+		return ""
+	}
+	return findTownRoot(cwd)
+}
+
 // findTownRoutes searches for routes.jsonl at the town level.
 // It walks up from currentBeadsDir to find the town root, then loads routes
 // from <townRoot>/.beads/routes.jsonl.
 // Returns (routes, townRoot). Returns nil routes if not in an orchestrator town or no routes found.
+//
+// IMPORTANT: This function handles symlinked .beads directories correctly.
+// When .beads is a symlink (e.g., ~/gt/.beads -> ~/gt/olympus/.beads), we must
+// use findTownRoot() starting from CWD to determine the actual town root rather
+// than starting from currentBeadsDir, which may be the resolved symlink path.
 func findTownRoutes(currentBeadsDir string) ([]Route, string) {
 	// First try the current beads dir (works if we're already at town level)
 	routes, err := LoadRoutes(currentBeadsDir)
 	if err == nil && len(routes) > 0 {
-		// Return the parent of the beads dir as "town root" for path resolution
+		// Use findTownRoot() starting from CWD to determine the actual town root.
+		// We must NOT use currentBeadsDir as the starting point because if .beads
+		// is a symlink (e.g., ~/gt/.beads -> ~/gt/olympus/.beads), currentBeadsDir
+		// will be the resolved path (e.g., ~/gt/olympus/.beads) and walking up
+		// from there would find ~/gt/olympus as the town root instead of ~/gt.
+		townRoot := findTownRootFromCWD()
+		if townRoot != "" {
+			if os.Getenv("BD_DEBUG_ROUTING") != "" {
+				fmt.Fprintf(os.Stderr, "[routing] findTownRoutes: found routes in %s, townRoot=%s (via findTownRootFromCWD)\n", currentBeadsDir, townRoot)
+			}
+			return routes, townRoot
+		}
+		// Fallback to parent dir if not in a town structure (for non-Gas Town repos)
+		if os.Getenv("BD_DEBUG_ROUTING") != "" {
+			fmt.Fprintf(os.Stderr, "[routing] findTownRoutes: found routes in %s, townRoot=%s (fallback to parent dir)\n", currentBeadsDir, filepath.Dir(currentBeadsDir))
+		}
 		return routes, filepath.Dir(currentBeadsDir)
 	}
 
-	// Walk up to find town root
-	townRoot := findTownRoot(currentBeadsDir)
+	// Walk up from CWD to find town root
+	townRoot := findTownRootFromCWD()
 	if townRoot == "" {
 		return nil, "" // Not in a town
 	}
@@ -316,6 +348,10 @@ func findTownRoutes(currentBeadsDir string) ([]Route, string) {
 		return nil, "" // No town routes
 	}
 
+	if os.Getenv("BD_DEBUG_ROUTING") != "" {
+		fmt.Fprintf(os.Stderr, "[routing] findTownRoutes: loaded routes from %s, townRoot=%s\n", townBeadsDir, townRoot)
+	}
+
 	return routes, townRoot
 }