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/schema.sql

@@ -414,3 +414,55 @@ END $$;
 
 -- Remove the v2.0.5 arena_id column (replaced by the new Arena feature).
 ALTER TABLE tasks DROP COLUMN IF EXISTS arena_id;
+
+-- v2.x-tool-traces: per-call tool execution records for observability.
+CREATE TABLE IF NOT EXISTS tool_traces (
+  id               UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  session_id       UUID NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
+  chat_id          UUID NOT NULL REFERENCES chats(id) ON DELETE CASCADE,
+  message_id       UUID REFERENCES messages(id) ON DELETE SET NULL,
+  turn_number      INTEGER NOT NULL,
+  tool_name        TEXT NOT NULL,
+  tool_input       JSONB NOT NULL,
+  tool_output      TEXT,
+  started_at       TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
+  finished_at      TIMESTAMPTZ,
+  latency_ms       INTEGER,
+  tokens_used      INTEGER,
+  cache_tokens     INTEGER,
+  reasoning_tokens INTEGER,
+  error            TEXT,
+  outcome          TEXT,
+  created_at       TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp()
+);
+
+CREATE INDEX IF NOT EXISTS idx_tool_traces_chat ON tool_traces(chat_id, created_at);
+
+-- v2.x-tool-traces: active tool call state for in-flight instrumentation.
+CREATE TABLE IF NOT EXISTS tool_trace_states (
+  id               UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  session_id       UUID NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
+  chat_id          UUID NOT NULL REFERENCES chats(id) ON DELETE CASCADE,
+  message_id       UUID REFERENCES messages(id) ON DELETE SET NULL,
+  turn_number      INTEGER NOT NULL,
+  tool_name        TEXT NOT NULL,
+  tool_input       JSONB NOT NULL,
+  started_at       TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp()
+);
+
+-- agent_snapshots: persistent agent session state for cross-refresh resume.
+CREATE TABLE IF NOT EXISTS agent_snapshots (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  session_id UUID NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
+  chat_id UUID NOT NULL REFERENCES chats(id) ON DELETE CASCADE,
+  model TEXT NOT NULL,
+  agent TEXT,
+  mode TEXT,
+  turn_number INTEGER NOT NULL DEFAULT 0,
+  messages JSONB NOT NULL DEFAULT '[]'::jsonb,
+  tool_states JSONB NOT NULL DEFAULT '[]'::jsonb,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp()
+);
+CREATE INDEX IF NOT EXISTS idx_agent_snapshots_chat ON agent_snapshots(chat_id);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_agent_snapshots_chat_unique ON agent_snapshots(chat_id);