fix(exceptions): log the full stack trace in the global exception handler

[tmgbedu]

Problem

The global ExceptionHandler.report_exception() builds its log message via _build_context(), which only appended the traceback when the app was in debug mode. In production the ERROR log carried just the exception summary — e.g. ModuleNotFoundError: No module named 'app.agents.chat' — with no stack trace, so failures were effectively undiagnosable from logs.

Fix

_build_context() now always returns the full traceback.format_exception(...) output (matching the module's existing traceback convention). Whether the trace is shown to the HTTP client remains a separate, debug-gated decision in the FastAPI render layer (fastapi/exceptions.py), so this does not leak internals to end users — it only enriches server-side logs / stderr.

Tests

New tests/exceptions/test_handler.py:

• traceback is logged when not in debug (the regression),
• traceback is logged in debug too,
• traceback is printed to stderr when no logger is bound.

uv run pytest (excl. live-Postgres): 2053 passed, 7 skipped. Ruff clean.

Task #1347.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[tmgbedu]

Code review — PASS (task #1349)

Reviewed the diff, the render-layer for client exposure, and the new tests. (Note: posting as a comment, not an approval review, since GitHub won't let this account approve its own PR.)

Correctness

• _build_context() now unconditionally returns traceback.format_exception(...), fixing the original bug where production logs only got ExcType: message with no trace.
• Confirmed no other callers of _build_context/report_exception exist, so this is an isolated, safe change.

No client-facing leakage

• Checked fastapi/exceptions.py::HTTPExceptionHandler.render() — the HTTP response body is still gated on app.is_debug() and only returns {"message": "Server Error"} when not in debug. This PR only touches the server-side logging path (report_exception → Logger.error/stderr); the debug gate for what the client sees is untouched.

Tests

• Ran tests/exceptions/test_handler.py in isolation: 3/3 pass, covering the non-debug regression, debug-mode logging, and the no-logger stderr fallback.
• Ran the full suite (uv run pytest --ignore=tests/masoniteorm/postgres): 2053 passed, 7 skipped — matches the PR description.
• ruff check clean on changed files.
• The uv.lock diff just re-syncs the editable package's self-referential version metadata to match pyproject.toml (already 0.50.0 on both branches) — harmless, unrelated to the fix itself.

LGTM. Holding off on merge until QA (task #1348) signs off, per the coordination task.