Add T0.5 market heat IPO analysis

Request:
- Test whether subscription-period T0.5 market heat data can be captured and incorporated into IPO analysis.

Changes:
- Add an ipo_market_heat table for non-official market-heat snapshots.
- Add a VBKR/Jieli archive script for expected margin subscription multiples.
- Archive the 2026-06-15T18:40:00Z heat snapshot for 01392, 02335, 06067, 06106, and 06132.
- Add an experimental T0.5 overlay rule file and a Chinese cross-IPO trial report.
- Update archivist and analyst skills so T0.5 remains separate from official T1 allotment demand.

Verification:
- .venv/bin/python -m py_compile scripts/archive_t0_5_market_heat.py scripts/build_analysis_dataset.py scripts/update_sync_state.py
- Python sqlite3 PRAGMA integrity_check returned ok and foreign_key_check returned zero rows.
- Confirmed 5 ipo_market_heat rows and 5 t0_5_market_heat source_refs for the frozen snapshot.
- git diff --cached --check

Next useful context:
- T0.5 data is non-official and should be resampled during the subscription window, then compared against T1 official allotment results.

rules/ipo_score_v0_5_market_heat_trial.yaml

@@ -0,0 +1,55 @@
+version: ipo_score_v0_5_market_heat_trial
+effective_date: 2026-06-15
+status: experimental_overlay
+owner_skill: analyst
+base_model: ipo_score_v0
+
+purpose: >
+  Add a stage-safe T0.5 market-heat overlay to the transparent HK IPO
+  subscription model. T0.5 uses non-official subscription-period market
+  heat snapshots such as broker-aggregated margin subscription multiples.
+  It is designed to update a T0 watchlist before official T1 allotment
+  results are available.
+
+data_policy:
+  stage: T0_5_market_heat
+  allowed_inputs:
+    - margin_subscription_multiple
+    - provider
+    - observed_at
+    - subscription_deadline
+  forbidden_inputs:
+    - official_allotment_results
+    - public_oversubscription_times_from_T1
+    - international_oversubscription_times_from_T1
+    - grey_market_result
+    - post_listing_price_performance
+  caveat: >
+    T0.5 is a live, non-official signal. It must be stored with provider,
+    observed_at timestamp, source URL, and raw snapshot path. Do not treat it
+    as final HKEX allotment demand.
+
+score_components:
+  T0_5_market_heat:
+    margin_subscription_multiple:
+      source: broker_or_market_data_snapshot
+      points:
+        missing: 0
+        lt_10x: -3
+        gte_10_lt_100x: 0
+        gte_100_lt_1000x: 3
+        gte_1000_lt_5000x: 6
+        gte_5000x: 8
+
+decision_bands:
+  T0_plus_T0_5:
+    score_lt_5: weak_or_avoid
+    score_5_to_7: wait_for_T1
+    score_8_to_11: active_watch
+    score_gte_12: high_heat_watch
+
+comparison_policy:
+  - Compare raw margin multiples only among IPOs at a similar subscription lifecycle.
+  - If close dates differ, explicitly note early-stage versus near-deadline bias.
+  - Use T0.5 to upgrade or downgrade watchlist priority, not to replace T1 official demand.
+  - Freeze every T0.5 snapshot so later T1/D1 reviews can test whether the live heat signal helped.