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
+      ./gastown-fix-validate-recipient.patch
-      substituteInPlace internal/mail/router.go \
-        --replace-fail \
-          'if agentBeadToAddress(agent) == identity {' \
-          'if AddressToIdentity(agentBeadToAddress(agent)) == AddressToIdentity(identity) {'
-
       # Fix agentBeadToAddress to use title field for hq- prefixed beads
-      # Title should contain the address (e.g., "java/crew/americano")
+      ./gastown-fix-agent-bead-address-title.patch
-      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)'
-
       # Fix agentBeadToAddress to handle rig-specific prefixes (j-, sc-, etc.)
-      # Bead IDs like j-java-crew-americano should map to java/crew/americano
+      ./gastown-fix-agent-bead-rig-prefix.patch
-      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
-	}'
-
       # Fix crew/polecat home paths: remove incorrect /rig suffix
-      substituteInPlace internal/cmd/role.go \
+      ./gastown-fix-role-home-paths.patch
-        --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)'
-
       # Fix town root detection: don't map to Mayor (causes spurious mismatch warnings)
-      substituteInPlace internal/cmd/prime.go \
+      ./gastown-fix-town-root-detection.patch
-        --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" {'
-
       # Fix copyDir to handle symlinks (broken symlinks cause "no such file" errors)
-      # See: https://github.com/steveyegge/gastown/issues/TBD
+      ./gastown-fix-copydir-symlinks.patch
-      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() {'
-
       # 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
+      ./gastown-statusline-optimization.patch
-      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'
-    '';
 
     meta = with lib; {
       description = "Gas Town - multi-agent workspace manager by Steve Yegge";

home/roles/development/gastown-fix-agent-bead-address-title.patch

@@ -0,0 +1,16 @@
+diff --git a/internal/mail/router.go b/internal/mail/router.go
+index 0000000..1111111 100644
+--- a/internal/mail/router.go
++++ b/internal/mail/router.go
+@@ -326,7 +326,11 @@ func agentBeadToAddress(bead *agentBead) string {
+ 		}
+
+ 		// Fall back to parsing description for role_type and rig
+-		return parseAgentAddressFromDescription(bead.Description)
++		if bead.Title != "" && strings.Contains(bead.Title, "/") {
++			return bead.Title
++		}
++		return parseAgentAddressFromDescription(bead.Description)
+ 	}
+
+ 	// Handle gt- prefixed IDs (legacy format)

home/roles/development/gastown-fix-agent-bead-rig-prefix.patch

@@ -0,0 +1,36 @@
+diff --git a/internal/mail/router.go b/internal/mail/router.go
+index 0000000..1111111 100644
+--- a/internal/mail/router.go
++++ b/internal/mail/router.go
+@@ -330,8 +330,28 @@ func agentBeadToAddress(bead *agentBead) string {
+ 	}
+
+ 	// 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
+ 	}
+
+ 	// Strip prefix

home/roles/development/gastown-fix-copydir-symlinks.patch

@@ -0,0 +1,25 @@
+diff --git a/internal/git/git.go b/internal/git/git.go
+index 0000000..1111111 100644
+--- a/internal/git/git.go
++++ b/internal/git/git.go
+@@ -73,7 +73,18 @@ func copyDir(src, dest string) error {
+ 		srcPath := filepath.Join(src, entry.Name())
+ 		destPath := filepath.Join(dest, entry.Name())
+
+-		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() {
+ 			if err := copyDir(srcPath, destPath); err != nil {
+ 				return err
+ 			}

home/roles/development/gastown-fix-role-home-paths.patch

@@ -0,0 +1,19 @@
+diff --git a/internal/cmd/role.go b/internal/cmd/role.go
+index 0000000..1111111 100644
+--- a/internal/cmd/role.go
++++ b/internal/cmd/role.go
+@@ -326,11 +326,11 @@ func getRoleHome(role Role, rig, polecat, townRoot string) string {
+ 		if rig == "" || polecat == "" {
+ 			return ""
+ 		}
+-		return filepath.Join(townRoot, rig, "polecats", polecat, "rig")
++		return filepath.Join(townRoot, rig, "polecats", polecat)
+ 	case RoleCrew:
+ 		if rig == "" || polecat == "" {
+ 			return ""
+ 		}
+-		return filepath.Join(townRoot, rig, "crew", polecat, "rig")
++		return filepath.Join(townRoot, rig, "crew", polecat)
+ 	default:
+ 		return ""
+ 	}

home/roles/development/gastown-fix-town-root-detection.patch

@@ -0,0 +1,19 @@
+diff --git a/internal/cmd/prime.go b/internal/cmd/prime.go
+index 0000000..1111111 100644
+--- a/internal/cmd/prime.go
++++ b/internal/cmd/prime.go
+@@ -276,12 +276,12 @@ func detectRole(cwd, townRoot string) RoleInfo {
+
+ 	// Check for mayor role
+ 	// At town root, or in mayor/ or mayor/rig/
+ 	if relPath == "." || relPath == "" {
+-		ctx.Role = RoleMayor
+-		return ctx
++		return ctx // RoleUnknown - town root is shared space
+ 	}
++
++	// Check for mayor role: mayor/ or mayor/rig/
+ 	if len(parts) >= 1 && parts[0] == "mayor" {
+ 		ctx.Role = RoleMayor
+ 		return ctx
+ 	}

home/roles/development/gastown-fix-validate-recipient.patch

@@ -0,0 +1,13 @@
+diff --git a/internal/mail/router.go b/internal/mail/router.go
+index b864c069..4b6a045b 100644
+--- a/internal/mail/router.go
++++ b/internal/mail/router.go
+@@ -646,7 +646,7 @@ func (r *Router) validateRecipient(identity string) error {
+ 	}
+
+ 	for _, agent := range agents {
+-		if agentBeadToAddress(agent) == identity {
++		if AddressToIdentity(agentBeadToAddress(agent)) == AddressToIdentity(identity) {
+ 			return nil // Found matching agent
+ 		}
+ 	}

home/roles/development/gastown-statusline-optimization.patch

@@ -0,0 +1,136 @@
+diff --git a/internal/cmd/statusline.go b/internal/cmd/statusline.go
+index 0000000..1111111 100644
+--- a/internal/cmd/statusline.go
++++ b/internal/cmd/statusline.go
+@@ -6,6 +6,7 @@ import (
+ 	"os"
+ 	"path/filepath"
+ 	"sort"
+ 	"strings"
++	"time"
+
+ 	"github.com/spf13/cobra"
+ 	"github.com/steveyegge/gastown/internal/beads"
+@@ -15,6 +16,43 @@ import (
+ 	"github.com/steveyegge/gastown/internal/workspace"
+ )
+
++// 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
+ )
+@@ -32,6 +70,20 @@ func init() {
+ 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
+ 	var rigName, polecat, crew, issue, role string
+
+@@ -149,7 +201,12 @@ func runWorkerStatusLine(t *tmux.Tmux, session, rigName, polecat, crew, issue st
+
+ 	// Output
+ 	if len(parts) > 0 {
+-		fmt.Print(strings.Join(parts, " | ") + " |")
++		output := strings.Join(parts, " | ") + " |"
++		if statusLineSession != "" {
++			setStatusLineCache(statusLineSession, output)
++		}
++		fmt.Print(output)
+ 	}
+
+ 	return nil
+@@ -389,7 +446,12 @@ func runMayorStatusLine(t *tmux.Tmux) error {
+ 		}
+ 	}
+
+-	fmt.Print(strings.Join(parts, " | ") + " |")
++	output := strings.Join(parts, " | ") + " |"
++	if statusLineSession != "" {
++		setStatusLineCache(statusLineSession, output)
++	}
++	fmt.Print(output)
+ 	return nil
+ }
+
+@@ -458,7 +520,12 @@ func runDeaconStatusLine(t *tmux.Tmux) error {
+ 		}
+ 	}
+
+-	fmt.Print(strings.Join(parts, " | ") + " |")
++	output := strings.Join(parts, " | ") + " |"
++	if statusLineSession != "" {
++		setStatusLineCache(statusLineSession, output)
++	}
++	fmt.Print(output)
+ 	return nil
+ }
+
+@@ -526,7 +593,12 @@ func runWitnessStatusLine(t *tmux.Tmux, rigName string) error {
+ 		}
+ 	}
+
+-	fmt.Print(strings.Join(parts, " | ") + " |")
++	output := strings.Join(parts, " | ") + " |"
++	if statusLineSession != "" {
++		setStatusLineCache(statusLineSession, output)
++	}
++	fmt.Print(output)
+ 	return nil
+ }
+
+@@ -617,7 +689,12 @@ func runRefineryStatusLine(t *tmux.Tmux, rigName string) error {
+ 		}
+ 	}
+
+-	fmt.Print(strings.Join(parts, " | ") + " |")
++	output := strings.Join(parts, " | ") + " |"
++	if statusLineSession != "" {
++		setStatusLineCache(statusLineSession, output)
++	}
++	fmt.Print(output)
+ 	return nil
+ }
+