Add Python agent run trace

[xTRam1]

Summary

Adds structured tracing for custom Python agents. The SDK emits events for every stdout/stderr line, sub-agent call, extension action, and side-effect; the frontend (NaradaAI/frontend#1592) consumes these events and renders them on the observability dashboard.

What changes

narada-core — new Pydantic models

• PythonAgentRunTrace (step_type: pythonAgentRun) wrapping a run's full execution
• PythonTraceEvent discriminated union: stdout, stderr, subAgentCall, extensionAction, sideEffect
• Added to ApaStepTrace; parse_action_trace round-trips the new shape

narada-pyodide — chokepoint-based instrumentation so adding a new SDK method needs no trace-layer changes

• window.py:dispatch_request() wrapped → every window.agent(...) emits a subAgentCall event (covers success / error / timeout)
• window.py:_run_extension_action() wrapped → every extension action emits an extensionAction event
• utils.download_file / utils.render_html → sideEffect events
• All events flow through _narada_emit_trace_event(json_str), a Pyodide global the frontend registers

Payload safety — per-action summaries in _trace.summarize_request bound the persisted JSON size (hard caps on free-form strings; structured subsets for write_google_sheet, screenshot, agentic_selector, etc.).

Version bumps (coupled)

• narada-core: 0.0.17 → 0.0.18
• narada-pyodide: 0.0.43 → 0.0.45a2
• narada: 0.1.42 → 0.1.43 (repin narada-core==0.0.18 only, no code change)

Why bump narada too: if narada-core@0.0.18 (new variant) shipped without a matching narada bump, external Python SDK users would silently break on parse_action_trace ValidationError the moment a response they polled contained a nested Python custom agent run.

Example

This custom Python agent:

from narada import Agent, LocalBrowserWindow
import narada

window = LocalBrowserWindow()
await window.go_to_url(url="https://example.com", new_tab=True)

narada.render_html("<h1>Trace ordering test</h1>")
print("[A] after render_html")

narada.download_file("ordering-test.txt", "x")
print("[B] after download_file")

raise ValueError("intentional final traceback")

emits this trace (rendered by the frontend PR):

{
  "step_type": "pythonAgentRun",
  "status": "error",
  "duration_ms": 16028,
  "events": [
    { "kind": "extensionAction", "ts_start": 1777063298934, "ts_end": 1777063302993,
      "action_name": "go_to_url",
      "request_summary": { "url": "https://example.com", "new_tab": true },
      "status": "success" },
    { "kind": "sideEffect", "ts": 1777063302994,
      "effect_type": "render_html", "description": "Rendered HTML in a new tab" },
    { "kind": "stdout", "ts": 1777063302995, "text": "[A] after render_html" },
    { "kind": "sideEffect", "ts": 1777063302995,
      "effect_type": "download_file", "description": "Downloaded file: ordering-test.txt" },
    { "kind": "stdout", "ts": 1777063302996, "text": "[B] after download_file" },
    { "kind": "stderr", "ts": 1777063303004,
      "text": "Traceback (most recent call last):\n  File \"<exec>\", line 11, in <module>\nValueError: intentional final traceback\n" }
  ],
  "error_message": "Traceback ..."
}

Tests

38 unit tests in packages/narada-pyodide/tests/test_trace.py:

• Truncation edge cases (None, exact length, over cap)
• summarize_request / summarize_response per action type
• Event emitters: shape, timeout status, error-message truncation, optional-field omission
• End-to-end: every emitter's output round-trips through parse_action_trace into a valid PythonAgentRunTrace

Run (the narada / narada-pyodide namespace collision requires uninstalling narada first; see packages/narada-pyodide/tests/README.md):

uv pip uninstall narada
uv run --package narada-pyodide pytest packages/narada-pyodide/tests/

Publish steps (manual, post-merge)

uv build --package narada-core    && uv publish --token <pypi-token>
uv build --package narada-pyodide && uv publish --token <pypi-token>
uv build --package narada         && uv publish --token <pypi-token>

git tag narada-core@0.0.18 narada-pyodide@0.0.45a2 narada@0.1.43
git push origin narada-core@0.0.18 narada-pyodide@0.0.45a2 narada@0.1.43

Frontend PR NaradaAI/frontend#1592 pins narada-pyodide==0.0.45a2 and micropips it at Pyodide runtime, so the new versions must be on PyPI before that PR ships.

[xTRam1]

Since we are removing the hard caps, we probably don't need these right?

[xTRam1]

Move these to a model.py file inside a tracing folder.