refactor(development): move gastown patches to separate files

Replace inline postPatch substituteInPlace calls with proper unified
diff patch files, following the pattern established by beads.

This improves maintainability:
- Each patch is in its own file with clear naming
- Patches use proper unified diff format
- Easier to review, update, and track individual fixes
- Default.nix is cleaner (237 lines of substituteInPlace -> 15 lines)

Patches included:
- gastown-fix-validate-recipient.patch
- gastown-fix-agent-bead-address-title.patch
- gastown-fix-agent-bead-rig-prefix.patch
- gastown-fix-role-home-paths.patch
- gastown-fix-town-root-detection.patch
- gastown-fix-copydir-symlinks.patch
- gastown-statusline-optimization.patch

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

home/roles/development/default.nix

@@ -41,251 +41,24 @@ let
     ];
 
     # Bug fixes not yet merged upstream
-    postPatch = ''
+    # Each patch is stored in a separate file for clarity and maintainability
+    patches = [
       # Fix validateRecipient bug: normalize addresses before comparison
-      # See: https://github.com/steveyegge/gastown/issues/TBD
-      substituteInPlace internal/mail/router.go \
-        --replace-fail \
-          'if agentBeadToAddress(agent) == identity {' \
-          'if AddressToIdentity(agentBeadToAddress(agent)) == AddressToIdentity(identity) {'
-
+      ./gastown-fix-validate-recipient.patch
       # Fix agentBeadToAddress to use title field for hq- prefixed beads
-      # Title should contain the address (e.g., "java/crew/americano")
-      substituteInPlace internal/mail/router.go \
-        --replace-fail \
-          'return parseAgentAddressFromDescription(bead.Description)' \
-          'if bead.Title != "" && strings.Contains(bead.Title, "/") { return bead.Title }; return parseAgentAddressFromDescription(bead.Description)'
-
+      ./gastown-fix-agent-bead-address-title.patch
       # Fix agentBeadToAddress to handle rig-specific prefixes (j-, sc-, etc.)
-      # Bead IDs like j-java-crew-americano should map to java/crew/americano
-      substituteInPlace internal/mail/router.go \
-        --replace-fail \
-          '// Handle gt- prefixed IDs (legacy format)
-	if !strings.HasPrefix(id, "gt-") {
-		return "" // Not a valid agent bead ID
-	}' \
-          '// Handle rig-specific prefixes: <prefix>-<rig>-<role>-<name>
-	// Examples: j-java-crew-americano -> java/crew/americano
-	idParts := strings.Split(id, "-")
-	if len(idParts) >= 3 {
-		for i, part := range idParts {
-			if part == "crew" || part == "polecat" || part == "polecats" {
-				if i >= 1 && i < len(idParts)-1 {
-					rig := idParts[i-1]
-					name := strings.Join(idParts[i+1:], "-")
-					return rig + "/" + part + "/" + name
-				}
-			}
-			if part == "witness" || part == "refinery" {
-				if i >= 1 {
-					return idParts[i-1] + "/" + part
-				}
-			}
-		}
-	}
-
-	// Handle gt- prefixed IDs (legacy format)
-	if !strings.HasPrefix(id, "gt-") {
-		return "" // Not a valid agent bead ID
-	}'
-
+      ./gastown-fix-agent-bead-rig-prefix.patch
       # Fix crew/polecat home paths: remove incorrect /rig suffix
-      substituteInPlace internal/cmd/role.go \
-        --replace-fail \
-          'return filepath.Join(townRoot, rig, "polecats", polecat, "rig")' \
-          'return filepath.Join(townRoot, rig, "polecats", polecat)' \
-        --replace-fail \
-          'return filepath.Join(townRoot, rig, "crew", polecat, "rig")' \
-          'return filepath.Join(townRoot, rig, "crew", polecat)'
-
+      ./gastown-fix-role-home-paths.patch
       # Fix town root detection: don't map to Mayor (causes spurious mismatch warnings)
-      substituteInPlace internal/cmd/prime.go \
-        --replace-fail \
-          'if relPath == "." || relPath == "" {
-		ctx.Role = RoleMayor
-		return ctx
-	}
-	if len(parts) >= 1 && parts[0] == "mayor" {' \
-          'if relPath == "." || relPath == "" {
-		return ctx // RoleUnknown - town root is shared space
-	}
-
-	// Check for mayor role: mayor/ or mayor/rig/
-	if len(parts) >= 1 && parts[0] == "mayor" {'
-
+      ./gastown-fix-town-root-detection.patch
       # Fix copyDir to handle symlinks (broken symlinks cause "no such file" errors)
-      # See: https://github.com/steveyegge/gastown/issues/TBD
-      substituteInPlace internal/git/git.go \
-        --replace-fail \
-          'if entry.IsDir() {' \
-          '// Handle symlinks (recreate them, do not follow)
-		if entry.Type()&os.ModeSymlink != 0 {
-			linkTarget, err := os.Readlink(srcPath)
-			if err != nil {
-				return err
-			}
-			if err := os.Symlink(linkTarget, destPath); err != nil {
-				return err
-			}
-			continue
-		}
-
-		if entry.IsDir() {'
-
+      ./gastown-fix-copydir-symlinks.patch
       # Statusline optimization: skip detached sessions and cache results
       # Reduces Dolt CPU from ~70% to ~20% by avoiding beads queries for sessions nobody is watching
-      # See: https://github.com/steveyegge/gastown/issues/TBD
-      substituteInPlace internal/cmd/statusline.go \
-        --replace-fail \
-          '"strings"' \
-          '"strings"
-	"time"' \
-        --replace-fail \
-          'var (
-	statusLineSession string
-)' \
-          '// statusLineCacheTTL is how long cached status output remains valid.
-const statusLineCacheTTL = 10 * time.Second
-
-// statusLineCachePath returns the cache file path for a session.
-func statusLineCachePath(session string) string {
-	return filepath.Join(os.TempDir(), fmt.Sprintf("gt-status-%s", session))
-}
-
-// getStatusLineCache returns cached status if fresh, empty string otherwise.
-func getStatusLineCache(session string) string {
-	path := statusLineCachePath(session)
-	info, err := os.Stat(path)
-	if err != nil {
-		return ""
-	}
-	if time.Since(info.ModTime()) > statusLineCacheTTL {
-		return ""
-	}
-	data, err := os.ReadFile(path)
-	if err != nil {
-		return ""
-	}
-	return string(data)
-}
-
-// setStatusLineCache writes status to cache file.
-func setStatusLineCache(session, status string) {
-	path := statusLineCachePath(session)
-	_ = os.WriteFile(path, []byte(status), 0644)
-}
-
-var (
-	statusLineSession string
-)' \
-        --replace-fail \
-          'func runStatusLine(cmd *cobra.Command, args []string) error {
-	t := tmux.NewTmux()
-
-	// Get session environment' \
-          'func runStatusLine(cmd *cobra.Command, args []string) error {
-	t := tmux.NewTmux()
-
-	// Optimization: skip expensive beads queries for detached sessions
-	if statusLineSession != "" {
-		if !t.IsSessionAttached(statusLineSession) {
-			fmt.Print("○ |")
-			return nil
-		}
-		// Check cache for attached sessions too
-		if cached := getStatusLineCache(statusLineSession); cached != "" {
-			fmt.Print(cached)
-			return nil
-		}
-	}
-
-	// Get session environment' \
-        --replace-fail \
-          '	// Output
-	if len(parts) > 0 {
-		fmt.Print(strings.Join(parts, " | ") + " |")
-	}
-
-	return nil
-}
-
-func runMayorStatusLine(t *tmux.Tmux) error {' \
-          '	// Output
-	if len(parts) > 0 {
-		output := strings.Join(parts, " | ") + " |"
-		if statusLineSession != "" {
-			setStatusLineCache(statusLineSession, output)
-		}
-		fmt.Print(output)
-	}
-
-	return nil
-}
-
-func runMayorStatusLine(t *tmux.Tmux) error {' \
-        --replace-fail \
-          'fmt.Print(strings.Join(parts, " | ") + " |")
-	return nil
-}
-
-// runDeaconStatusLine outputs status for the deacon session.' \
-          'output := strings.Join(parts, " | ") + " |"
-	if statusLineSession != "" {
-		setStatusLineCache(statusLineSession, output)
-	}
-	fmt.Print(output)
-	return nil
-}
-
-// runDeaconStatusLine outputs status for the deacon session.' \
-        --replace-fail \
-          'fmt.Print(strings.Join(parts, " | ") + " |")
-	return nil
-}
-
-// runWitnessStatusLine outputs status for a witness session.
-// Shows: crew count, hook or mail preview' \
-          'output := strings.Join(parts, " | ") + " |"
-	if statusLineSession != "" {
-		setStatusLineCache(statusLineSession, output)
-	}
-	fmt.Print(output)
-	return nil
-}
-
-// runWitnessStatusLine outputs status for a witness session.
-// Shows: crew count, hook or mail preview' \
-        --replace-fail \
-          'fmt.Print(strings.Join(parts, " | ") + " |")
-	return nil
-}
-
-// runRefineryStatusLine outputs status for a refinery session.' \
-          'output := strings.Join(parts, " | ") + " |"
-	if statusLineSession != "" {
-		setStatusLineCache(statusLineSession, output)
-	}
-	fmt.Print(output)
-	return nil
-}
-
-// runRefineryStatusLine outputs status for a refinery session.' \
-        --replace-fail \
-          'fmt.Print(strings.Join(parts, " | ") + " |")
-	return nil
-}
-
-// isSessionWorking detects' \
-          'output := strings.Join(parts, " | ") + " |"
-	if statusLineSession != "" {
-		setStatusLineCache(statusLineSession, output)
-	}
-	fmt.Print(output)
-	return nil
-}
-
-// isSessionWorking detects'
-    '';
+      ./gastown-statusline-optimization.patch
+    ];
 
     meta = with lib; {
       description = "Gas Town - multi-agent workspace manager by Steve Yegge";