phase 2: symbol registry validation, seed data, nix dev shell

- Enhanced CompanyCreate with ticker format validation (1-10 uppercase letters)
- Enhanced SourceCreate with pydantic validators for source_type, access_policy, config URLs
- Added /health endpoint to symbol registry
- Seed data: 10 companies (AAPL, MSFT, NVDA, AMZN, GOOGL, JPM, JNJ, XOM, TSLA, META)
- Seed sources: Alpha Vantage (market), NewsAPI (news), SEC EDGAR (filings), Alpaca (paper trading)
- Seed watchlist: 'Starter 10' with all companies and aliases
- Added flake.nix dev shell (nixos-25.11) with Python 3.12, ruff, pytest, kubectl, helm
- 30 passing tests, lint clean, Docker build verified

tests/test_symbol_registry.py

@@ -0,0 +1,105 @@
+"""Tests for symbol registry validation and seed data."""
+import pytest
+from pydantic import ValidationError
+
+# Import after path setup
+from services.symbol_registry.app import CompanyCreate, SourceCreate, VALID_SOURCE_TYPES
+from services.symbol_registry.seed import COMPANIES, ALIASES, SOURCES_PER_COMPANY
+
+
+# --- CompanyCreate validation ---
+
+def test_ticker_uppercased():
+    c = CompanyCreate(ticker="aapl", legal_name="Apple Inc.")
+    assert c.ticker == "AAPL"
+
+
+def test_ticker_strips_whitespace():
+    c = CompanyCreate(ticker="  MSFT  ", legal_name="Microsoft")
+    assert c.ticker == "MSFT"
+
+
+def test_ticker_rejects_numbers():
+    with pytest.raises(ValidationError):
+        CompanyCreate(ticker="123", legal_name="Bad")
+
+
+def test_ticker_rejects_empty():
+    with pytest.raises(ValidationError):
+        CompanyCreate(ticker="", legal_name="Bad")
+
+
+def test_ticker_rejects_too_long():
+    with pytest.raises(ValidationError):
+        CompanyCreate(ticker="ABCDEFGHIJK", legal_name="Bad")
+
+
+def test_ticker_rejects_special_chars():
+    with pytest.raises(ValidationError):
+        CompanyCreate(ticker="AA-PL", legal_name="Bad")
+
+
+# --- SourceCreate validation ---
+
+def test_source_valid_types():
+    for st in VALID_SOURCE_TYPES:
+        s = SourceCreate(source_type=st, source_name="test")
+        assert s.source_type == st
+
+
+def test_source_rejects_invalid_type():
+    with pytest.raises(ValidationError):
+        SourceCreate(source_type="invalid_type", source_name="test")
+
+
+def test_source_rejects_invalid_access_policy():
+    with pytest.raises(ValidationError):
+        SourceCreate(source_type="market_api", source_name="test", access_policy="secret")
+
+
+def test_source_validates_config_url():
+    s = SourceCreate(
+        source_type="market_api",
+        source_name="test",
+        config={"base_url": "https://api.example.com"},
+    )
+    assert s.config["base_url"] == "https://api.example.com"
+
+
+def test_source_rejects_bad_config_url():
+    with pytest.raises(ValidationError):
+        SourceCreate(
+            source_type="market_api",
+            source_name="test",
+            config={"base_url": "not-a-url"},
+        )
+
+
+# --- Seed data integrity ---
+
+def test_seed_companies_have_required_fields():
+    for c in COMPANIES:
+        assert c["ticker"]
+        assert c["legal_name"]
+        assert c["exchange"]
+        assert c["sector"]
+
+
+def test_seed_companies_unique_tickers():
+    tickers = [c["ticker"] for c in COMPANIES]
+    assert len(tickers) == len(set(tickers))
+
+
+def test_seed_aliases_reference_valid_tickers():
+    tickers = {c["ticker"] for c in COMPANIES}
+    for ticker in ALIASES:
+        assert ticker in tickers, f"Alias references unknown ticker: {ticker}"
+
+
+def test_seed_sources_have_valid_types():
+    for src in SOURCES_PER_COMPANY:
+        assert src["source_type"] in VALID_SOURCE_TYPES
+
+
+def test_seed_has_ten_companies():
+    assert len(COMPANIES) == 10