session-memory: map signals to catalog recommendations via covers (WP-0010 follow-up)

Closes the gap where recurring_error suggestions showed generic 'Investigate'
instead of the curated recommendation. Added a covers[] field to SolutionPattern
(lowercase substrings a pattern's recommendation also applies to) + Catalog.find_for
(exact key first, then covers match against signal key+locus). Retro now resolves
recommendations through find_for. Tagged the read-before-edit pattern with
covers=['file has not been read','modified since read','file_not_read'] (v1.0.1).
Live: file-not-read suggestions across all repos now inherit 'Read the file before
Edit/Write'. 6 new tests; suite 158/158.

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

tests/test_retro_build.py

@@ -55,6 +55,26 @@ def test_recommendation_from_catalog(tmp_path):
     assert r["suggestions"][0]["recommendation"] == "Stop and diagnose before retrying"
 
 
+def test_recurring_error_inherits_recommendation_via_covers(tmp_path):
+    cat = Catalog(str(tmp_path / "catalog"))
+    cat.upsert(SolutionPattern(
+        id="sp-rbe", name="Read before edit", version="1.0.0", polarity="problem",
+        problem="edit before read",
+        resolutions=[Resolution(summary="Read the file first before Edit/Write")],
+        covers=["file has not been read"]))
+    digs = []
+    for i in range(2):
+        d = _digest(f"claude:{i}", "r1", "2026-06-0{}T10:00:00Z".format(i + 1))
+        d["error_snippets"] = [{
+            "fingerprint": "<tool_use_error>file has not been read yet. read it first...",
+            "sample": "File has not been read yet", "count": 2, "tool": "Edit"}]
+        digs.append(d)
+    r = weekly_retro(digs, catalog=cat, since="2026-05-30T00:00:00Z", until="2026-06-08T00:00:00Z")
+    rec_err = [s for s in r["suggestions"] if s["signal_type"] == "recurring_error"]
+    assert rec_err, "expected a recurring_error suggestion"
+    assert rec_err[0]["recommendation"] == "Read the file first before Edit/Write"
+
+
 def test_caps_three_per_repo():
     # five distinct problem signals in one repo -> capped at 3
     digs = []