Add concrete IPO stage dates to reports

Request:
- Include the concrete T0, T1, T2, and D1 dates in every analyst report.

Changes:
- Add a Stage Calendar section to the single-IPO report generator.
- Require analyst reports to include ticker-specific T0 subscription window, T1 allotment-result date, T2 grey-market date/window, and D1 listing date.
- Update the 06106 T0 report with its concrete stage dates.
- Document the requirement in the analyst skill, README, and rule change log.

Verification:
- Ran py_compile for scripts/generate_ipo_report.py.
- Generated a 06106 dry-run report and checked the stage calendar.
- Ran git diff --check.

Next useful context:
- For 06106, T0 is 2026-06-15 to 2026-06-18, T1/T2 is 2026-06-23, and D1 is 2026-06-24.

rules/rule_change_log.md

@@ -1,5 +1,27 @@
 # Rule Change Log
 
+## 2026-06-15 - Add concrete stage dates to reports
+
+Request:
+
+- Every analyst report should note the specific dates behind T0, T1, T2, and D1 for the covered IPO.
+
+Change:
+
+- Added a `Stage Calendar` section to the single-ticker report generator.
+- Required analyst reports to show the ticker-specific T0 subscription window, T1 allotment-result date, T2 grey-market date/window, and D1 listing date.
+- Updated the 06106 T0 report to include its concrete stage dates.
+
+Rationale:
+
+- The T0/T1/T2/D1 labels are project analysis stages, so reports should always bind them to actual calendar dates for the IPO under review.
+
+Verification:
+
+- Generated a 06106 dry-run report and checked the stage calendar.
+- Ran py_compile for the report generator.
+- Ran git diff --check.
+
 ## 2026-06-15 - Clarify short-exit IPO strategy horizon
 
 Request: