wire up /agent/execute and /agent/stop endpoints

- Add runSessionAgent: streaming variant of runAgent that PATCHes VIBN DB
  after every LLM turn and tool call so frontend can poll live output
- Track changed files from write_file / replace_in_file tool calls
- Add /agent/execute: receives sessionId + giteaRepo + task, clones repo,
  scopes workspace to appPath, runs Coder agent async (returns 202 immediately)
- Add /agent/stop: sets stopped flag; agent checks between turns and exits cleanly
- Agent does NOT commit on completion — leaves changes for user review/approval

Made-with: Cursor

src/server.ts

@@ -6,6 +6,7 @@ import * as crypto from 'crypto';
 import { execSync } from 'child_process';
 import { createJob, getJob, listJobs, updateJob } from './job-store';
 import { runAgent } from './agent-runner';
+import { runSessionAgent } from './agent-session-runner';
 import { AGENTS } from './agents';
 import { ToolContext } from './tools';
 import { PROTECTED_GITEA_REPOS } from './tools/security';
@@ -343,6 +344,116 @@ app.post('/webhook/gitea', (req: Request, res: Response) => {
         });
 });
 
+// ---------------------------------------------------------------------------
+// Agent Execute — VIBN Build > Code > Agent tab
+//
+// Receives a task from the VIBN frontend, runs the Coder agent against
+// the project's Gitea repo, and streams progress back to the VIBN DB
+// via PATCH /api/projects/[id]/agent/sessions/[sid].
+//
+// This endpoint returns immediately (202) and runs the agent async so
+// the browser can close without killing the loop.
+// ---------------------------------------------------------------------------
+
+// Track active sessions for stop support
+const activeSessions = new Map<string, { stopped: boolean }>();
+
+app.post('/agent/execute', async (req: Request, res: Response) => {
+    const { sessionId, projectId, appName, appPath, giteaRepo, task } = req.body as {
+        sessionId?: string;
+        projectId?: string;
+        appName?: string;
+        appPath?: string;
+        giteaRepo?: string;
+        task?: string;
+    };
+
+    if (!sessionId || !projectId || !appPath || !task) {
+        res.status(400).json({ error: 'sessionId, projectId, appPath and task are required' });
+        return;
+    }
+
+    const vibnApiUrl = process.env.VIBN_API_URL ?? 'https://vibnai.com';
+
+    // Register session as active
+    const sessionState = { stopped: false };
+    activeSessions.set(sessionId, sessionState);
+
+    // Respond immediately — execution is async
+    res.status(202).json({ sessionId, status: 'running' });
+
+    // Build workspace context — clone/update the Gitea repo if provided
+    let ctx: ReturnType<typeof buildContext>;
+    try {
+        ctx = buildContext(giteaRepo);
+    } catch (err) {
+        const msg = err instanceof Error ? err.message : String(err);
+        console.error('[agent/execute] buildContext failed:', msg);
+        // Notify VIBN DB of failure
+        fetch(`${vibnApiUrl}/api/projects/${projectId}/agent/sessions/${sessionId}`, {
+            method: 'PATCH',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ status: 'failed', error: msg }),
+        }).catch(() => {});
+        activeSessions.delete(sessionId);
+        return;
+    }
+
+    // Scope workspace to the app subdirectory so the agent works there naturally
+    if (appPath) {
+        const path = require('path') as typeof import('path');
+        ctx.workspaceRoot = path.join(ctx.workspaceRoot, appPath);
+        const fs = require('fs') as typeof import('fs');
+        fs.mkdirSync(ctx.workspaceRoot, { recursive: true });
+    }
+
+    const agentConfig = AGENTS['Coder'];
+    if (!agentConfig) {
+        fetch(`${vibnApiUrl}/api/projects/${projectId}/agent/sessions/${sessionId}`, {
+            method: 'PATCH',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ status: 'failed', error: 'Coder agent not registered' }),
+        }).catch(() => {});
+        activeSessions.delete(sessionId);
+        return;
+    }
+
+    // Run the streaming agent loop (fire and forget)
+    runSessionAgent(agentConfig, task, ctx, {
+        sessionId,
+        projectId,
+        vibnApiUrl,
+        appPath,
+        isStopped: () => sessionState.stopped,
+    })
+    .catch(err => {
+        const msg = err instanceof Error ? err.message : String(err);
+        console.error(`[agent/execute] session ${sessionId} crashed:`, msg);
+        fetch(`${vibnApiUrl}/api/projects/${projectId}/agent/sessions/${sessionId}`, {
+            method: 'PATCH',
+            headers: { 'Content-Type': 'application/json' },
+            body: JSON.stringify({ status: 'failed', error: msg }),
+        }).catch(() => {});
+    })
+    .finally(() => {
+        activeSessions.delete(sessionId);
+    });
+});
+
+app.post('/agent/stop', (req: Request, res: Response) => {
+    const { sessionId } = req.body as { sessionId?: string };
+    if (!sessionId) { res.status(400).json({ error: 'sessionId required' }); return; }
+
+    const session = activeSessions.get(sessionId);
+    if (session) {
+        session.stopped = true;
+        res.json({ ok: true, message: 'Stop signal sent — agent will halt after current step.' });
+    } else {
+        // Session may have already finished
+        res.json({ ok: true, message: 'Session not active (may have already completed).' });
+    }
+});
+
 // ---------------------------------------------------------------------------
 // Generate — thin structured-generation endpoint (no session, no system prompt)
 // Use this for one-shot tasks like architecture recommendations.