fix(extensions): hyphenate command names in the Forge post-install listing (#3669)

After `specify extension add`, the "Provided commands" summary hyphenated
command names only for Cline. For a Forge project the names were printed in
dotted form (e.g. `speckit.test-ext.hello`), but Forge registers them
hyphenated (`speckit-test-ext-hello`), so the printed names didn't match
what the user actually invokes in Forge.

Extend the existing Cline handling to Forge via `format_forge_command_name`,
completing the Forge command-name parity already fixed for hook invocations
(#3641) and the init next-steps panel (#3642).

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

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/specify_cli/extensions/_commands.py

@@ -623,16 +623,22 @@ def extension_add(
         for warning in manifest.warnings:
             console.print(f"\n[yellow]⚠  Compatibility warning:[/yellow] {_escape_markup(str(warning))}")
 
-        is_cline = load_init_options(project_root).get("ai") == "cline"
+        selected_ai = load_init_options(project_root).get("ai")
+        is_cline = selected_ai == "cline"
+        is_forge = selected_ai == "forge"
 
         if is_cline:
             from specify_cli.integrations.cline import format_cline_command_name
+        if is_forge:
+            from specify_cli.integrations.forge import format_forge_command_name
 
         console.print("\n[bold cyan]Provided commands:[/bold cyan]")
         for cmd in manifest.commands:
             cmd_name = cmd['name']
             if is_cline:
                 cmd_name = format_cline_command_name(cmd_name)
+            elif is_forge:
+                cmd_name = format_forge_command_name(cmd_name)
             console.print(f"  • {_escape_markup(str(cmd_name))} - {_escape_markup(str(cmd.get('description', '')))}")
 
         # Report agent skills registration