session-memory: session-quality filter (WP-0005 T01)

detect/quality.py: is_real_coding_session drops health-checks / smoke-tests /
interrupted / trivially-short sessions (event floor, repo present, substantive
tool activity, non-trivial prompt). Wired into run_detect so signals only form
over real sessions — fixes the abandoned false-positive. [detect.quality] knobs;
existing detect/curate fixtures made realistic. 8 new tests; suite 80/80.

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

tests/test_detect_entrypoint.py

@@ -15,6 +15,9 @@ def _digest(uid, flavor, repo, **markers):
         "cost": {"input_tokens": 10, "output_tokens": 1},
         "markers": {"errors": markers.get("errors", 0), "retries": markers.get("retries", 0),
                     "test_runs": 0, "edits": 0, "human_interventions": 0},
+        # fields the quality filter (WP-0005 T01) checks — real coding session
+        "event_count": 40, "first_prompt": "Fix the failing build and retry the suite",
+        "tool_histogram": {"Bash": 20, "Edit": 12, "Read": 8},
     }