fix: deploy SessionStart hooks in gt install for Mayor role

When users run `claude` directly at the town root instead of
`gt mayor start`, Claude wasn't receiving the Mayor delegation
protocol because `gt prime` never ran.

Root cause: `gt install` created CLAUDE.md but not the
.claude/settings.json with SessionStart hooks that run `gt prime`.

This adds `claude.EnsureSettingsForRole(absPath, "mayor")` to
`gt install` to ensure the Mayor always gets proper Claude settings
with hooks that enforce the delegation protocol.

Fixes #84

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

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

internal/cmd/install.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/spf13/cobra"
 	"github.com/steveyegge/gastown/internal/beads"
+	"github.com/steveyegge/gastown/internal/claude"
 	"github.com/steveyegge/gastown/internal/config"
 	"github.com/steveyegge/gastown/internal/deps"
 	"github.com/steveyegge/gastown/internal/formula"
@@ -189,6 +190,15 @@ func runInstall(cmd *cobra.Command, args []string) error {
 		fmt.Printf("   ✓ Created CLAUDE.md\n")
 	}
 
+	// Ensure Mayor has Claude settings with SessionStart hooks.
+	// This ensures gt prime runs on Claude startup, which outputs the Mayor
+	// delegation protocol - critical for preventing direct implementation.
+	if err := claude.EnsureSettingsForRole(absPath, "mayor"); err != nil {
+		fmt.Printf("   %s Could not create .claude/settings.json: %v\n", style.Dim.Render("⚠"), err)
+	} else {
+		fmt.Printf("   ✓ Created .claude/settings.json\n")
+	}
+
 	// Initialize town-level beads database (optional)
 	// Town beads (hq- prefix) stores mayor mail, cross-rig coordination, and handoffs.
 	// Rig beads are separate and have their own prefixes.