feat(lapdog): add Gemini CLI hook support

[mr-lee]

Summary

• add Gemini CLI command-hook ingestion and LLMObs span assembly
• register Gemini hook routes, including trajectory-compatible /capture/gemini/{EventType}
• add lapdog gemini launcher support that generates and installs a Gemini extension for the selected local port
• document Gemini hook usage

Validation

• pytest tests/test_gemini_hooks.py tests/test_lapdog_gemini_extension.py tests/test_pi_hooks.py tests/test_lapdog_claude_hooks.py -q
• pytest tests/test_gemini_hooks.py tests/test_pi_hooks.py tests/test_claude_hooks.py tests/test_claude_steps.py tests/test_lapdog_claude_hooks.py -q
• python -m flake8 ddapm_test_agent/gemini_hooks.py lapdog/cli.py tests/test_gemini_hooks.py tests/test_lapdog_gemini_extension.py
• git diff --check

[mr-lee]

Pushed e5f5a6d to make the Gemini PR explicitly cover the live badge/status behavior.

The Gemini implementation already had the right lifecycle: BeforeAgent creates the root span with duration=0, and AfterAgent finalizes it with elapsed duration. I added regression coverage against the same static-app-facing paths used by LLM Observability:

• internal Gemini spans keep the active root duration at 0
• query-rewriter event list returns custom.duration=0 for the active root span
• trace detail returns root span duration=0 while active
• after AfterAgent, event list returns the finalized positive duration

Validation:

• pytest tests/test_gemini_hooks.py tests/test_lapdog_gemini_extension.py tests/test_llmobs_event_platform.py -q => 49 passed
• git diff --check => clean

[mr-lee]

Updated this PR with an additional live-status fix in commit 814a34b.\n\nWhat changed:\n- Kept active Gemini root spans at duration 0 for the LLM Obs live badge.\n- Ensured finalized Gemini root/step/tool spans get a positive duration even if finalization happens in the same clock tick, so they exit the live/running UI state.\n- Applied the same finalized-duration helper to Claude paths too, since the previous CI run exposed the same issue in tests/test_claude_steps.py::test_stop_finalizes_open_step on Windows.\n- Added a Gemini same-tick regression through the static-app-facing list endpoint.\n\nValidation:\n- pytest tests/test_claude_steps.py::test_stop_finalizes_open_step -q\n- pytest tests/test_gemini_hooks.py::test_gemini_same_tick_finalization_exits_live_badge -q\n- pytest tests/test_claude_hooks.py tests/test_claude_steps.py tests/test_gemini_hooks.py tests/test_lapdog_gemini_extension.py tests/test_llmobs_event_platform.py -q => 79 passed\n- git diff --check\n\nI also tried the broad local test command, but this machine still fails to start the test agent because OTLP gRPC cannot bind [::]:4317, which cascades into setup errors; the focused suites above cover the changed code paths.