fix: skip-write on no-op merge, bash subprocess, dynamic integration list

- _merge_vscode_settings() only writes when keys were actually added
- update-context.sh uses exec subprocess like PS1 version
- Unknown integration error lists available integrations dynamically

Author: mnriem

src/specify_cli/__init__.py

@@ -1977,11 +1977,12 @@ def init(
     # Auto-promote: --ai copilot → integration path with a nudge
     use_integration = False
     if integration:
-        from .integrations import get_integration
+        from .integrations import INTEGRATION_REGISTRY, get_integration
         resolved_integration = get_integration(integration)
         if not resolved_integration:
             console.print(f"[red]Error:[/red] Unknown integration: '{integration}'")
-            console.print("[yellow]Available integrations:[/yellow] copilot")
+            available = ", ".join(sorted(INTEGRATION_REGISTRY))
+            console.print(f"[yellow]Available integrations:[/yellow] {available}")
             raise typer.Exit(1)
         use_integration = True
         # Map integration key to the ai_assistant variable for downstream compatibility

src/specify_cli/integrations/copilot/__init__.py

@@ -178,13 +178,19 @@ def _merge_vscode_settings(src: Path, dst: Path) -> None:
             )
             return
 
+        changed = False
         for key, value in new_settings.items():
             if key not in existing:
                 existing[key] = value
+                changed = True
             elif isinstance(existing[key], dict) and isinstance(value, dict):
                 for sub_key, sub_value in value.items():
                     if sub_key not in existing[key]:
                         existing[key][sub_key] = sub_value
+                        changed = True
+
+        if not changed:
+            return
 
         dst.write_text(
             json.dumps(existing, indent=4) + "\n", encoding="utf-8"

src/specify_cli/integrations/copilot/scripts/update-context.sh

@@ -11,25 +11,12 @@
 # refactored to support SPECKIT_SOURCE_ONLY (guard the main logic)
 # before sourcing will work.
 #
-# Sources common.sh and the shared update-agent-context functions,
-# then calls update_agent_file with the copilot target path.
+# Until then, this delegates to the shared script as a subprocess.
 
 set -euo pipefail
 
 REPO_ROOT="${REPO_ROOT:-$(git rev-parse --show-toplevel 2>/dev/null || pwd)}"
 
-# Source shared utilities
-source "$REPO_ROOT/.specify/scripts/bash/common.sh"
-
-# Source update-agent-context functions (parse_plan_data, update_agent_file, etc.)
-# SPECKIT_SOURCE_ONLY prevents the shared script from running its own main().
-export SPECKIT_SOURCE_ONLY=1
-source "$REPO_ROOT/.specify/scripts/bash/update-agent-context.sh"
-
-# Gather feature paths and parse plan data
-_paths_output=$(get_feature_paths) || exit 1
-eval "$_paths_output"
-parse_plan_data "$IMPL_PLAN"
-
-# Create or update the copilot instructions file
-update_agent_file "$REPO_ROOT/.github/copilot-instructions.md" "GitHub Copilot"
+# Invoke shared update-agent-context script as a separate process.
+# Sourcing is unsafe until that script guards its main logic.
+exec "$REPO_ROOT/.specify/scripts/bash/update-agent-context.sh" copilot