feat(server): Add readOnly mode to Cursor provider for read-only operations

Adds a readOnly option to ExecuteOptions that controls whether the
Cursor CLI runs with --force flag (allows edits) or without (suggest-only).

Read-only routes now pass readOnly: true:
- generate-spec.ts, generate-features-from-spec.ts (we write files ourselves)
- validate-issue.ts, generate-suggestions.ts (analysis only)
- describe-file.ts, describe-image.ts (description only)
- generate-plan.ts, enhance.ts (text generation only)

Routes that implement features (auto-mode-service, agent-service) keep
the default (readOnly: false) to allow file modifications.

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

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

apps/server/src/routes/app-spec/generate-features-from-spec.ts

@@ -132,6 +132,7 @@ IMPORTANT: Do not ask for clarification. The specification is provided above. Ge
       maxTurns: 250,
       allowedTools: ['Read', 'Glob', 'Grep'],
       abortController,
+      readOnly: true, // Feature generation only reads code, doesn't write
     })) {
       messageCount++;
 

apps/server/src/routes/app-spec/generate-spec.ts

@@ -132,6 +132,7 @@ ${JSON.stringify(specOutputSchema, null, 2)}`;
       maxTurns: 250,
       allowedTools: ['Read', 'Glob', 'Grep'],
       abortController,
+      readOnly: true, // Spec generation only reads code, we write the spec ourselves
     })) {
       messageCount++;