feat: Paseo-like orchestrator Phase 1-2 — trace system, session persistence, timeline, run_command, auto-fix loop

Phase 1: Trace System + Observability
- tool_traces DB table + insert/update service
- tool_trace_start/tool_trace_finish WS frames (contracts + FE types)
- Instrumented tool-phase.ts with timing around every tool call
- GET /api/chats/:id/traces paginated endpoint
- Trace viewer frontend (collapsible panel with timing bars + token breakdown)

Phase 2: Session Persistence + Resume
- agent_snapshots table (UPSERT per chat, persisted on turn boundaries)
- save/load/delete service functions
- Agent snapshot sent on WS reconnect
- Session timeline view (vertical timeline with scroll-to + restore)

Tooling:
- run_command tool (execFile, 30s timeout, 32KB cap, path-guarded)
- Auto-fix loop: after write tools, runs pnpm build, injects errors into next turn

apps/server/src/services/inference/tool-phase.ts

@@ -20,6 +20,7 @@ import { resolveGrantRoot } from '../grant_resolver.js';
 import { stripToolMarkup } from './tool-call-parser.js';
 import { repairToolInput } from './tool-input-repair.js';
 import type { FailureKind } from './mistake-tracker.js';
+import { insertToolTrace, updateToolTrace } from '../tool-traces.js';
 import type {
   InferenceContext,
   StreamResult,
@@ -175,6 +176,7 @@ export async function executeToolPhase(
   session: Session,
   projectRoot: string,
   agent?: Agent | null,
+  turnNumber?: number,
 ): Promise<ToolPhaseResult> {
   const { sessionId, chatId, assistantMessageId } = args;
   const content = stripToolMarkup(result.content, { final: true });
@@ -378,11 +380,53 @@ export async function executeToolPhase(
         });
         return;
       }
+      // tool_trace instrumentation - start
+      const traceId = crypto.randomUUID();
+      const traceStartTime = Date.now();
+      const startedAtIso = new Date().toISOString();
+      insertToolTrace(ctx.sql, {
+        session_id: sessionId,
+        chat_id: chatId,
+        message_id: assistantMessageId,
+        turn_number: turnNumber ?? 0,
+        tool_name: tc.name,
+        tool_input: tc.args as Record<string, unknown>,
+      }).catch(() => {});
+      ctx.publish(sessionId, {
+        type: 'tool_trace_start',
+        trace_id: traceId,
+        message_id: assistantMessageId,
+        chat_id: chatId,
+        tool_name: tc.name,
+        tool_input: tc.args as Record<string, unknown>,
+        started_at: startedAtIso,
+      });
       const tres = await executeToolCall(
         projectRoot, tc, session.allowed_read_paths,
         { sql: ctx.sql, sessionId },
         ctx.hooks, sessionId,
       );
+      // tool_trace instrumentation - finish
+      const finishedAtIso = new Date().toISOString();
+      const latencyMs = Date.now() - traceStartTime;
+      updateToolTrace(ctx.sql, traceId, {
+        finished_at: finishedAtIso,
+        ...(tres.outcome === 'success' && tres.output != null ? { tool_output: JSON.stringify(tres.output) } : {}),
+        latency_ms: latencyMs,
+        outcome: tres.outcome,
+        ...(tres.error ? { error: tres.error } : {}),
+      }).catch(() => {});
+      ctx.publish(sessionId, {
+        type: 'tool_trace_finish',
+        trace_id: traceId,
+        message_id: assistantMessageId,
+        chat_id: chatId,
+        tool_name: tc.name,
+        finished_at: finishedAtIso,
+        outcome: tres.outcome,
+        latency_ms: latencyMs,
+        ...(tres.error ? { error: tres.error } : {}),
+      });
       // vWhale: PostToolUse hook (best-effort, non-blocking).
       if (ctx.hooks) {
         ctx.hooks.run('PostToolUse', {