fix(sec): A3 slice-1 review — read-only resolution, error propagation, fair-access

Addresses the slice-1 review:

1. Resolution is now read-only (A1 transaction contract). resolve_ciks /
   fetch_sic_updates compute proposals and mutate nothing; a new
   apply_ticker_updates issues the writes, called only in promote — so a failed
   validation can't leak ticker changes on the framework's failure commit.
2. Only 404 means "missing". Added SecNotFoundError; daily_index /
   latest_index_date catch only that. 403, exhausted 429, 5xx, timeouts, and
   transport/parse errors now propagate instead of looking like "no index".
3. Fair-access enforced when opening a REAL client (transport=None): reject
   blank/placeholder/non-email User-Agent and sub-0.11s spacing. Mock transports
   skip it (tests use 0 spacing).
4. submissions(include_history=False) by default — only the one-time full
   backfill fetches the history shards; SIC/incremental work makes no extra
   requests.

Plus: retry transient 5xx/network errors and honor Retry-After during the 1 GB
backfill; compose_revision rejects a missing index date (no "None:..." revision).

Re-verified live vs real SEC (fair-access validation passes, shard merge intact).
Tests: 18 (added error propagation, read-only resolution, fair-access, recent-only
submissions, reject-None revision).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/unit/test_sec_universe.py

@@ -1,4 +1,5 @@
-"""Tests for CIK/SIC resolution and the composite-revision fingerprint."""
+"""Tests for CIK/SIC resolution (read-only), apply-in-promote, and the
+composite-revision fingerprint."""
 
 from __future__ import annotations
 
@@ -40,11 +41,11 @@ class FakeSecClient:
     async def company_tickers(self):
         return dict(self._tickers)
 
-    async def submissions(self, cik):
+    async def submissions(self, cik, *, include_history=False):
         return self._submissions[int(cik)]
 
 
-async def test_resolve_ciks_sets_cik_and_returns_mapping(factory):
+async def test_resolve_ciks_is_read_only_and_proposes_updates(factory):
     async with factory() as s:
         for sym in ["AAPL", "GOOGL", "GOOG", "ZZZZ"]:  # ZZZZ not in SEC
             s.add(Ticker(symbol=sym))
@@ -52,35 +53,47 @@ async def test_resolve_ciks_sets_cik_and_returns_mapping(factory):
 
     client = FakeSecClient({"AAPL": 320193, "GOOGL": 1652044, "GOOG": 1652044})
     async with factory() as s:
-        mapping = await su.resolve_ciks(s, client)
-        await s.commit()
+        resolved = await su.resolve_ciks(s, client)
+        assert not s.dirty and not s.new  # NOTHING mutated during resolution
+        await s.rollback()
 
-    assert mapping == {"AAPL": 320193, "GOOGL": 1652044, "GOOG": 1652044}
+    assert resolved.symbol_to_cik == {"AAPL": 320193, "GOOGL": 1652044, "GOOG": 1652044}
+    assert len(resolved.cik_updates) == 3  # AAPL, GOOGL, GOOG (ZZZZ unresolved)
+    assert set(resolved.cik_to_ticker_ids) == {320193, 1652044}
+
+    # Read-only really means the DB is untouched until apply.
     async with factory() as s:
         ciks = {t.symbol: t.cik for t in (await s.execute(select(Ticker))).scalars()}
-    assert ciks["AAPL"] == "0000320193"
-    assert ciks["GOOGL"] == ciks["GOOG"] == "0001652044"  # multi-class share CIK
-    assert ciks["ZZZZ"] is None  # unresolved stays null
+    assert all(v is None for v in ciks.values())
 
 
-async def test_refresh_sic_updates_all_tickers_of_a_cik(factory):
+async def test_apply_ticker_updates_writes_cik_and_sic(factory):
     async with factory() as s:
         for sym in ["GOOGL", "GOOG"]:
-            s.add(Ticker(symbol=sym, cik="0001652044"))
+            s.add(Ticker(symbol=sym))
         await s.commit()
 
     client = FakeSecClient(
-        {}, submissions={1652044: {"sic": "7370", "sic_description": "Services-Computer"}}
+        {"GOOGL": 1652044, "GOOG": 1652044},
+        submissions={1652044: {"sic": "7370", "sic_description": "Services-Computer"}},
     )
     async with factory() as s:
-        n = await su.refresh_sic(s, client, [1652044])
+        resolved = await su.resolve_ciks(s, client)
+        sic_updates = await su.fetch_sic_updates(client, resolved.cik_to_ticker_ids)
+        counts = await su.apply_ticker_updates(s, resolved, sic_updates)
         await s.commit()
 
-    assert n == 1
+    assert counts == {"cik_updates": 2, "sic_updates": 2}
     async with factory() as s:
-        rows = {t.symbol: (t.sic, t.sic_description) for t in (await s.execute(select(Ticker))).scalars()}
-    assert rows["GOOGL"] == ("7370", "Services-Computer")
-    assert rows["GOOG"] == ("7370", "Services-Computer")
+        rows = {t.symbol: (t.cik, t.sic, t.sic_description) for t in (await s.execute(select(Ticker))).scalars()}
+    assert rows["GOOGL"] == ("0001652044", "7370", "Services-Computer")
+    assert rows["GOOG"] == ("0001652044", "7370", "Services-Computer")
+
+
+async def test_fetch_sic_updates_is_read_only(factory):
+    client = FakeSecClient({}, submissions={1: {"sic": "1", "sic_description": "x"}})
+    updates = await su.fetch_sic_updates(client, {1: [10, 11]})
+    assert updates == [(10, "1", "x"), (11, "1", "x")]  # proposals only, no DB touched
 
 
 def test_universe_fingerprint_changes_on_membership():
@@ -93,11 +106,13 @@ def test_universe_fingerprint_changes_on_membership():
     assert a != remapped  # changed CIK mapping forces a new revision
 
 
+def test_compose_revision_rejects_missing_index_date():
+    with pytest.raises(ValueError):
+        su.compose_revision(None, "abc", {"AAPL": 320193})
+
+
 def test_compose_revision_and_index_hash():
-    rows = [
-        {"cik": 320193, "accession": "a-1"},
-        {"cik": 66740, "accession": "b-2"},
-    ]
+    rows = [{"cik": 320193, "accession": "a-1"}, {"cik": 66740, "accession": "b-2"}]
     h1 = su.index_content_hash(rows)
     h2 = su.index_content_hash(list(reversed(rows)))
     assert h1 == h2  # order-independent