feat: expand magic prompts coverage and split generation prompts (#835)

- Add configurable visible/instructions prompt families for commit/PR generation, PR checks/comments flows, and git conflict resolution helpers.
- Refactor prompt sending to explicit visible + synthetic parts instead of newline-based splitting, with legacy override migration for old keys.
- Polish Magic Prompts settings UX with grouped sidebar entries, tooltip-based descriptions, AI icon, and validation that visible prompts cannot be empty across web and VS Code runtimes.

packages/web/server/lib/opencode/core-routes.js

@@ -161,6 +161,7 @@ export const registerCommonRequestMiddleware = (app, dependencies) => {
       req.path.startsWith('/api/projects') ||
       req.path.startsWith('/api/fs') ||
       req.path.startsWith('/api/git') ||
+      req.path.startsWith('/api/magic-prompts') ||
       req.path.startsWith('/api/prompts') ||
       req.path.startsWith('/api/terminal') ||
       req.path.startsWith('/api/opencode') ||

packages/web/server/lib/opencode/feature-routes-runtime.js

@@ -2,6 +2,7 @@ import { registerFsRoutes } from '../fs/routes.js';
 import { registerQuotaRoutes } from '../quota/routes.js';
 import { registerGitHubRoutes } from '../github/routes.js';
 import { registerGitRoutes } from '../git/routes.js';
+import { registerMagicPromptRoutes } from '../magic-prompts/routes.js';
 import { registerConfigEntityRoutes } from './config-entity-routes.js';
 import { registerSettingsUtilityRoutes } from './core-routes.js';
 import { registerProjectIconRoutes } from './project-icon-routes.js';
@@ -196,6 +197,11 @@ export const createFeatureRoutesRuntime = (dependencies) => {
     registerQuotaRoutes(app, { getQuotaProviders });
     registerGitHubRoutes(app);
     registerGitRoutes(app);
+    registerMagicPromptRoutes(app, {
+      fsPromises,
+      path,
+      openchamberDataDir,
+    });
     registerFsRoutes(app, {
       os,
       path,