feat(extensions,presets): add priority-based resolution ordering

Add priority field to extension and preset registries for deterministic
template resolution when multiple sources provide the same template.

Extensions:
- Add `list_by_priority()` method to ExtensionRegistry
- Add `--priority` option to `extension add` command
- Add `extension set-priority` command
- Show priority in `extension list` and `extension info`
- Preserve priority during `extension update`
- Update RFC documentation

Presets:
- Add `preset set-priority` command
- Show priority in `preset info` output
- Use priority ordering in PresetResolver for extensions

Both systems:
- Lower priority number = higher precedence (default: 10)
- Backwards compatible with legacy entries (missing priority defaults to 10)
- Comprehensive test coverage including backwards compatibility

Closes #1845
Closes #1854

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

Author: iamaeroplane

extensions/RFC-EXTENSION-SYSTEM.md

@@ -359,12 +359,15 @@ specify extension add jira
       "installed_at": "2026-01-28T14:30:00Z",
       "source": "catalog",
       "manifest_hash": "sha256:abc123...",
-      "enabled": true
+      "enabled": true,
+      "priority": 10
     }
   }
 }
 ```
 
+**Priority Field**: Extensions are ordered by `priority` (lower = higher precedence). Default is 10. Used for template resolution when multiple extensions provide the same template.
+
 ### 3. Configuration
 
 ```bash
@@ -1085,10 +1088,10 @@ $ specify extension list
 
 Installed Extensions:
   ✓ jira (v1.0.0) - Jira Integration
-    Commands: 3 | Hooks: 2 | Status: Enabled
+    Commands: 3 | Hooks: 2 | Priority: 10 | Status: Enabled
 
   ✓ linear (v0.9.0) - Linear Integration
-    Commands: 1 | Hooks: 1 | Status: Enabled
+    Commands: 1 | Hooks: 1 | Priority: 10 | Status: Enabled
 ```
 
 **Options:**
@@ -1200,6 +1203,7 @@ Next steps:
 - `--version VERSION`: Install specific version
 - `--dev PATH`: Install from local path (development mode)
 - `--no-register`: Skip command registration (manual setup)
+- `--priority NUMBER`: Set resolution priority (lower = higher precedence, default 10)
 
 #### `specify extension remove NAME`
 
@@ -1280,6 +1284,29 @@ $ specify extension disable jira
 To re-enable: specify extension enable jira
 ```
 
+#### `specify extension set-priority NAME PRIORITY`
+
+Change the resolution priority of an installed extension.
+
+```bash
+$ specify extension set-priority jira 5
+
+✓ Extension 'Jira Integration' priority changed: 10 → 5
+
+Lower priority = higher precedence in template resolution
+```
+
+**Priority Values:**
+
+- Lower numbers = higher precedence (checked first in resolution)
+- Default priority is 10
+- Must be a positive integer (1 or higher)
+
+**Use Cases:**
+
+- Ensure a critical extension's templates take precedence
+- Override default resolution order when multiple extensions provide similar templates
+
 ---
 
 ## Compatibility & Versioning

src/specify_cli/__init__.py

@@ -2210,6 +2210,10 @@ def preset_info(
         if license_val:
             console.print(f"  License:     {license_val}")
         console.print("\n  [green]Status: installed[/green]")
+        # Get priority from registry
+        pack_metadata = manager.registry.get(pack_id)
+        priority = pack_metadata.get("priority", 10) if pack_metadata else 10
+        console.print(f"  [dim]Priority:[/dim] {priority}")
         console.print()
         return
 
@@ -2241,6 +2245,53 @@ def preset_info(
     console.print()
 
 
+@preset_app.command("set-priority")
+def preset_set_priority(
+    pack_id: str = typer.Argument(help="Preset ID"),
+    priority: int = typer.Argument(help="New priority (lower = higher precedence)"),
+):
+    """Set the resolution priority of an installed preset."""
+    from .presets import PresetManager
+
+    project_root = Path.cwd()
+
+    # Check if we're in a spec-kit project
+    specify_dir = project_root / ".specify"
+    if not specify_dir.exists():
+        console.print("[red]Error:[/red] Not a spec-kit project (no .specify/ directory)")
+        console.print("Run this command from a spec-kit project root")
+        raise typer.Exit(1)
+
+    # Validate priority
+    if priority < 1:
+        console.print("[red]Error:[/red] Priority must be a positive integer (1 or higher)")
+        raise typer.Exit(1)
+
+    manager = PresetManager(project_root)
+
+    # Check if preset is installed
+    if not manager.registry.is_installed(pack_id):
+        console.print(f"[red]Error:[/red] Preset '{pack_id}' is not installed")
+        raise typer.Exit(1)
+
+    # Get current metadata
+    metadata = manager.registry.get(pack_id)
+    if metadata is None:
+        console.print(f"[red]Error:[/red] Preset '{pack_id}' not found in registry (corrupted state)")
+        raise typer.Exit(1)
+
+    old_priority = metadata.get("priority", 10)
+    if old_priority == priority:
+        console.print(f"[yellow]Preset '{pack_id}' already has priority {priority}[/yellow]")
+        raise typer.Exit(0)
+
+    # Update priority
+    manager.registry.update(pack_id, {"priority": priority})
+
+    console.print(f"[green]✓[/green] Preset '{pack_id}' priority changed: {old_priority} → {priority}")
+    console.print("\n[dim]Lower priority = higher precedence in template resolution[/dim]")
+
+
 # ===== Preset Catalog Commands =====
 
 
@@ -2576,8 +2627,9 @@ def extension_list(
             status_color = "green" if ext["enabled"] else "red"
 
             console.print(f"  [{status_color}]{status_icon}[/{status_color}] [bold]{ext['name']}[/bold] (v{ext['version']})")
+            console.print(f"     [dim]{ext['id']}[/dim]")
             console.print(f"     {ext['description']}")
-            console.print(f"     Commands: {ext['command_count']} | Hooks: {ext['hook_count']} | Status: {'Enabled' if ext['enabled'] else 'Disabled'}")
+            console.print(f"     Commands: {ext['command_count']} | Hooks: {ext['hook_count']} | Priority: {ext['priority']} | Status: {'Enabled' if ext['enabled'] else 'Disabled'}")
             console.print()
 
     if available or all_extensions:
@@ -2765,6 +2817,7 @@ def extension_add(
     extension: str = typer.Argument(help="Extension name or path"),
     dev: bool = typer.Option(False, "--dev", help="Install from local directory"),
     from_url: Optional[str] = typer.Option(None, "--from", help="Install from custom URL"),
+    priority: int = typer.Option(10, "--priority", help="Resolution priority (lower = higher precedence, default 10)"),
 ):
     """Install an extension."""
     from .extensions import ExtensionManager, ExtensionCatalog, ExtensionError, ValidationError, CompatibilityError
@@ -2794,7 +2847,7 @@ def extension_add(
                     console.print(f"[red]Error:[/red] No extension.yml found in {source_path}")
                     raise typer.Exit(1)
 
-                manifest = manager.install_from_directory(source_path, speckit_version)
+                manifest = manager.install_from_directory(source_path, speckit_version, priority=priority)
 
             elif from_url:
                 # Install from URL (ZIP file)
@@ -2827,7 +2880,7 @@ def extension_add(
                     zip_path.write_bytes(zip_data)
 
                     # Install from downloaded ZIP
-                    manifest = manager.install_from_zip(zip_path, speckit_version)
+                    manifest = manager.install_from_zip(zip_path, speckit_version, priority=priority)
                 except urllib.error.URLError as e:
                     console.print(f"[red]Error:[/red] Failed to download from {from_url}: {e}")
                     raise typer.Exit(1)
@@ -2871,7 +2924,7 @@ def extension_add(
 
                 try:
                     # Install from downloaded ZIP
-                    manifest = manager.install_from_zip(zip_path, speckit_version)
+                    manifest = manager.install_from_zip(zip_path, speckit_version, priority=priority)
                 finally:
                     # Clean up downloaded ZIP
                     if zip_path.exists():
@@ -3113,6 +3166,8 @@ def extension_info(
 
         console.print()
         console.print("[green]✓ Installed[/green]")
+        priority = metadata.get("priority", 10)
+        console.print(f"[dim]Priority:[/dim] {priority}")
         console.print(f"\nTo remove: specify extension remove {resolved_installed_id}")
         return
 
@@ -3206,6 +3261,9 @@ def _print_extension_info(ext_info: dict, manager):
     install_allowed = ext_info.get("_install_allowed", True)
     if is_installed:
         console.print("[green]✓ Installed[/green]")
+        metadata = manager.registry.get(ext_info['id'])
+        priority = metadata.get("priority", 10) if metadata else 10
+        console.print(f"[dim]Priority:[/dim] {priority}")
         console.print(f"\nTo remove: specify extension remove {ext_info['id']}")
     elif install_allowed:
         console.print("[yellow]Not installed[/yellow]")
@@ -3470,6 +3528,10 @@ def extension_update(
                         if "installed_at" in backup_registry_entry:
                             new_metadata["installed_at"] = backup_registry_entry["installed_at"]
 
+                        # Preserve the original priority
+                        if "priority" in backup_registry_entry:
+                            new_metadata["priority"] = backup_registry_entry["priority"]
+
                         # If extension was disabled before update, disable it again
                         if not backup_registry_entry.get("enabled", True):
                             new_metadata["enabled"] = False
@@ -3716,6 +3778,52 @@ def extension_disable(
     console.print(f"To re-enable: specify extension enable {extension_id}")
 
 
+@extension_app.command("set-priority")
+def extension_set_priority(
+    extension: str = typer.Argument(help="Extension ID or name"),
+    priority: int = typer.Argument(help="New priority (lower = higher precedence)"),
+):
+    """Set the resolution priority of an installed extension."""
+    from .extensions import ExtensionManager
+
+    project_root = Path.cwd()
+
+    # Check if we're in a spec-kit project
+    specify_dir = project_root / ".specify"
+    if not specify_dir.exists():
+        console.print("[red]Error:[/red] Not a spec-kit project (no .specify/ directory)")
+        console.print("Run this command from a spec-kit project root")
+        raise typer.Exit(1)
+
+    # Validate priority
+    if priority < 1:
+        console.print("[red]Error:[/red] Priority must be a positive integer (1 or higher)")
+        raise typer.Exit(1)
+
+    manager = ExtensionManager(project_root)
+
+    # Resolve extension ID from argument (handles ambiguous names)
+    installed = manager.list_installed()
+    extension_id, display_name = _resolve_installed_extension(extension, installed, "set-priority")
+
+    # Get current metadata
+    metadata = manager.registry.get(extension_id)
+    if metadata is None:
+        console.print(f"[red]Error:[/red] Extension '{extension_id}' not found in registry (corrupted state)")
+        raise typer.Exit(1)
+
+    old_priority = metadata.get("priority", 10)
+    if old_priority == priority:
+        console.print(f"[yellow]Extension '{display_name}' already has priority {priority}[/yellow]")
+        raise typer.Exit(0)
+
+    # Update priority
+    manager.registry.update(extension_id, {"priority": priority})
+
+    console.print(f"[green]✓[/green] Extension '{display_name}' priority changed: {old_priority} → {priority}")
+    console.print("\n[dim]Lower priority = higher precedence in template resolution[/dim]")
+
+
 def main():
     app()
 

src/specify_cli/extensions.py

@@ -324,6 +324,20 @@ def is_installed(self, extension_id: str) -> bool:
         """
         return extension_id in self.data["extensions"]
 
+    def list_by_priority(self) -> List[tuple]:
+        """Get all installed extensions sorted by priority.
+
+        Lower priority number = higher precedence (checked first).
+
+        Returns:
+            List of (extension_id, metadata) tuples sorted by priority
+        """
+        extensions = self.data["extensions"]
+        return sorted(
+            extensions.items(),
+            key=lambda item: item[1].get("priority", 10),
+        )
+
 
 class ExtensionManager:
     """Manages extension lifecycle: installation, removal, updates."""
@@ -440,14 +454,16 @@ def install_from_directory(
         self,
         source_dir: Path,
         speckit_version: str,
-        register_commands: bool = True
+        register_commands: bool = True,
+        priority: int = 10,
     ) -> ExtensionManifest:
         """Install extension from a local directory.
 
         Args:
             source_dir: Path to extension directory
             speckit_version: Current spec-kit version
             register_commands: If True, register commands with AI agents
+            priority: Resolution priority (lower = higher precedence, default 10)
 
         Returns:
             Installed extension manifest
@@ -497,6 +513,7 @@ def install_from_directory(
             "source": "local",
             "manifest_hash": manifest.get_hash(),
             "enabled": True,
+            "priority": priority,
             "registered_commands": registered_commands
         })
 
@@ -505,13 +522,15 @@ def install_from_directory(
     def install_from_zip(
         self,
         zip_path: Path,
-        speckit_version: str
+        speckit_version: str,
+        priority: int = 10,
     ) -> ExtensionManifest:
         """Install extension from ZIP file.
 
         Args:
             zip_path: Path to extension ZIP file
             speckit_version: Current spec-kit version
+            priority: Resolution priority (lower = higher precedence, default 10)
 
         Returns:
             Installed extension manifest
@@ -554,7 +573,7 @@ def install_from_zip(
                 raise ValidationError("No extension.yml found in ZIP file")
 
             # Install from extracted directory
-            return self.install_from_directory(extension_dir, speckit_version)
+            return self.install_from_directory(extension_dir, speckit_version, priority=priority)
 
     def remove(self, extension_id: str, keep_config: bool = False) -> bool:
         """Remove an installed extension.
@@ -643,6 +662,7 @@ def list_installed(self) -> List[Dict[str, Any]]:
                     "version": metadata.get("version", "unknown"),
                     "description": manifest.description,
                     "enabled": metadata.get("enabled", True),
+                    "priority": metadata.get("priority", 10),
                     "installed_at": metadata.get("installed_at"),
                     "command_count": len(manifest.commands),
                     "hook_count": len(manifest.hooks)
@@ -655,6 +675,7 @@ def list_installed(self) -> List[Dict[str, Any]]:
                     "version": metadata.get("version", "unknown"),
                     "description": "⚠️ Corrupted extension",
                     "enabled": False,
+                    "priority": metadata.get("priority", 10),
                     "installed_at": metadata.get("installed_at"),
                     "command_count": 0,
                     "hook_count": 0