Add browser dashboard, run tracing, and logged navigation decisions

- dashboard.py: stdlib http.server + JSON API (tree/trace/dream/status,
  POST submit/relabel); static/ single-page Redux-DevTools-style inspector
- trace.py: runs.jsonl lifecycle events keyed by run_id
- scheduler/skills/skill: every decision carries run_id; navigation choices
  now logged (navigate:category/leaf); requeues stamp meta.parent_run
- cli: 'dashboard' subcommand; config.json untracked per-machine (see
  config.example.json)

tests/test_dashboard_api.py

@@ -0,0 +1,148 @@
+"""Dashboard API tests against a real stdlib HTTP server on an ephemeral port.
+
+The scheduler is constructed with the lazy SemIfEngine (never loaded), so this
+runs anywhere without SemIf. Submit degrades to a JSON error, which is the
+expected behaviour on the thin dev box; relabel works against a seeded log.
+"""
+
+import json
+import threading
+import urllib.error
+import urllib.request
+from http.server import ThreadingHTTPServer
+
+from semif_agent.dashboard import DashboardHandler
+from semif_agent.decisions import DecisionRequest, DecisionResult, Option
+from semif_agent.engine import EngineConfig, SemIfEngine
+from semif_agent.llm import LLMClient
+from semif_agent.log import DecisionLog
+from semif_agent.scheduler import Scheduler
+from semif_agent.trace import TraceLog
+
+
+def build_scheduler(tmp_path):
+    log = DecisionLog(str(tmp_path / "decisions.jsonl"))
+    trace = TraceLog(str(tmp_path / "runs.jsonl"))
+    engine = SemIfEngine(EngineConfig())
+    llm = LLMClient(base_url="http://localhost:1/v1", model="test")
+    scheduler = Scheduler(
+        engine=engine,
+        llm=llm,
+        log=log,
+        config={"skills": {}},
+        trace=trace,
+    )
+    return scheduler
+
+
+def seed_decision(log, decision_id="abc123"):
+    request = DecisionRequest(
+        id=decision_id,
+        state="some state",
+        question="Pick one?",
+        options=[Option("a", "A."), Option("b", "B.")],
+    )
+    result = DecisionResult(
+        request=request, option_ids=["a", "b"], probabilities=[0.3, 0.7]
+    )
+    log.append(request, result, extra={"phase": "gate", "run_id": "run-1"})
+
+
+class Server:
+    def __init__(self, scheduler):
+        handler = type("Handler", (DashboardHandler,), {"scheduler": scheduler})
+        self.httpd = ThreadingHTTPServer(("127.0.0.1", 0), handler)
+        self.thread = threading.Thread(target=self.httpd.serve_forever, daemon=True)
+        self.thread.start()
+        self.port = self.httpd.server_address[1]
+
+    def get(self, path):
+        with urllib.request.urlopen(f"http://127.0.0.1:{self.port}{path}") as res:
+            return res.status, json.loads(res.read().decode("utf-8"))
+
+    def post(self, path, payload):
+        req = urllib.request.Request(
+            f"http://127.0.0.1:{self.port}{path}",
+            data=json.dumps(payload).encode("utf-8"),
+            headers={"Content-Type": "application/json"},
+            method="POST",
+        )
+        with urllib.request.urlopen(req) as res:
+            return res.status, json.loads(res.read().decode("utf-8"))
+
+    def close(self):
+        self.httpd.shutdown()
+        self.httpd.server_close()
+
+
+def test_tree_endpoint(tmp_path):
+    server = Server(build_scheduler(tmp_path))
+    try:
+        status, payload = server.get("/api/tree")
+        assert status == 200
+        assert "email" in payload["categories"]
+        assert any(s["name"] == "email.compose" for s in payload["categories"]["email"])
+    finally:
+        server.close()
+
+
+def test_trace_endpoint_empty(tmp_path):
+    server = Server(build_scheduler(tmp_path))
+    try:
+        status, payload = server.get("/api/trace")
+        assert status == 200
+        assert payload["runs"] == []
+    finally:
+        server.close()
+
+
+def test_submit_without_engine_returns_error_json(tmp_path):
+    scheduler = build_scheduler(tmp_path)
+    server = Server(scheduler)
+    try:
+        status, payload = server.post("/api/submit", {"text": "do something"})
+        assert status == 200
+        assert payload["status"] == "error"
+        assert "engine" in payload["detail"]
+    finally:
+        server.close()
+
+
+def test_relabel_roundtrip(tmp_path):
+    scheduler = build_scheduler(tmp_path)
+    seed_decision(scheduler.log)
+    server = Server(scheduler)
+    try:
+        status, payload = server.get("/api/trace")
+        assert status == 200
+        assert payload["runs"]
+        assert payload["runs"][0]["decisions"][0]["id"] == "abc123"
+
+        status, payload = server.post("/api/relabel", {"id": "abc123", "outcome": "b"})
+        assert status == 200
+        assert payload["ok"] is True
+
+        status, payload = server.get("/api/trace")
+        row = payload["runs"][0]["decisions"][0]
+        assert row["observed_outcome"] == "b"
+        assert row["label_source"] == "human"
+        assert row["cost"]["weight"] == 3.0
+
+        status, payload = server.post("/api/relabel", {"id": "nope", "outcome": "a"})
+        assert payload["ok"] is False
+    finally:
+        server.close()
+
+
+def test_submit_trace_event_recorded_even_when_engine_missing(tmp_path):
+    scheduler = build_scheduler(tmp_path)
+    server = Server(scheduler)
+    try:
+        server.post("/api/submit", {"text": "hello"})
+        status, payload = server.get("/api/trace")
+        runs = payload["runs"]
+        assert len(runs) == 1
+        kinds = [e["kind"] for e in runs[0]["events"]]
+        assert "submit" in kinds
+    finally:
+        server.close()