feat: override trade tab — manual order entry with auto-registration

Backend:
- OverrideOrderRequest/Response Pydantic models with ticker, quantity, price validators
- POST /api/trading/override/order endpoint (enqueue to Redis broker queue)
- auto_register_symbol() module for untracked ticker registration via Symbol Registry
- Unit tests (17) and property-based tests (3 x 100 examples)

Frontend:
- OverrideTradePanel component (order form + positions display)
- Override tab in TradingEngine page with URL search param navigation
- Override Trade button on Trading Controls page
- useSubmitOverrideOrder mutation hook
- MSW handler and 13 component/integration tests

Steering:
- Updated steering docs for Ubuntu dev machine with nvm/Node 24

.kiro/steering/development-process.md

@@ -1,12 +1,13 @@
 # Development Process — Test-Develop-Debug
 
 ## Local Environment
-- Python 3.12 via NixOS, virtualenv at `.venv/`
+- Ubuntu dev machine, Python 3.12, virtualenv at `.venv/`
 - Always use `.venv/bin/python` or activate with `source .venv/bin/activate` before running Python commands
-- For tools not available in `.venv/` (ruff, gh, etc.), use `nix-shell -p <pkg> --run "<cmd>"`
-- Node.js 24 for frontend; `frontend/` has its own `node_modules/`
-- Frontend tests: `cd frontend && npx vitest --run`
-- Python tests: `nix-shell -p ruff --run "ruff check services/"` then `python -m pytest tests/ -x --tb=short -q`
+- Node.js 24 via nvm — always load nvm before running Node/npm/npx commands:
+  `export NVM_DIR="$HOME/.nvm" && [ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh" && nvm use 24`
+- For tools not available in `.venv/` (ruff, gh, etc.), install via pip or apt as needed
+- Frontend tests: load nvm first, then `cd frontend && npx vitest --run`
+- Python tests: `.venv/bin/ruff check services/` then `.venv/bin/python -m pytest tests/ -x --tb=short -q`
 
 ## Workflow
 1. Write or update tests for the target behavior
@@ -22,7 +23,7 @@
 - Frontend: Vitest + MSW (Mock Service Worker) for deterministic API mocking, tests in `frontend/src/test/`
 - Run Python tests: `python -m pytest tests/ -x --tb=short -q`
 - Run frontend tests: `cd frontend && npx vitest --run`
-- Lint Python: `nix-shell -p ruff --run "ruff check services/"` (or `.venv/bin/ruff check services/`)
+- Lint Python: `.venv/bin/ruff check services/`
 - Ruff is pinned to `ruff==0.15.10` in `requirements.txt` — CI uses the same version
 - Ruff config: `ruff.toml` with `known-first-party = ["services"]` for consistent import sorting
 - Pre-existing test failures (not regressions): `test_extractor_prompts.py`, `test_extractor_schemas.py`, `test_filings_adapter.py`, `test_ollama_client.py`
@@ -36,8 +37,8 @@
   - `build-dashboard`: frontend/Dockerfile → GHCR (TypeScript strict mode — catches unused imports)
   - `build-superset`: docker/Dockerfile.superset → GHCR
 - CI handles all image builds and pushes — do NOT manually docker push
-- Check CI: `nix-shell -p gh --run "gh run list -L 3"` or `gh run list -L 3`
-- Re-run failed: `nix-shell -p gh --run "gh run rerun <id> --failed"`
+- Check CI: `gh run list -L 3`
+- Re-run failed: `gh run rerun <id> --failed`
 - View failure logs: `gh run view <id> --log-failed`
 
 ## Deploy