feat(continuation): formalize continuation proofs for claim and push (closes #189)

Extend #188 continuation mode with issue claim status evidence,
force-with-lease push reporting, canonical secret sweep helper, and
composite final-report checks wired into assess_issue_selection_final_report.

skills/llm-project-workflow/SKILL.md

@@ -379,11 +379,16 @@ Role-specific fields (append to the compact block):
   `Linked issue status:`, `Cleanup status:`
 - author tasks: `Selected issue:`, `Claim/comment status:`,
   `PR number opened:`, `No review/merge:` (explicit confirmation)
-- continuation tasks (#188): `Continuation mode:`, `Existing PR:`,
-  `PR author:`, `Branch:`, `Old PR head:`, `New PR head:`,
-  `Session authored PR:`, `Why continuation allowed:` — issues with open
-  PRs are excluded from fresh selection unless operator explicitly requests
-  continuation (`review_proofs.classify_issue_for_selection`,
+- continuation tasks (#188/#189): `Continuation mode:`, `Existing PR:`,
+  `PR author:`, `Issue claim status:`, `Branch:`, `Old PR head:`,
+  `New PR head:`, `Session authored PR:`, `Why continuation allowed:` —
+  when rebasing with `git push --force-with-lease`, also record
+  `Old remote head:`, `Lease head:`, `Pushed head:`, and confirm
+  `Push branch only:` (feature branch only). Use the canonical secret sweep
+  from `review_proofs.CANONICAL_SECRET_SWEEP_COMMAND` so runs are
+  comparable. Issues with open PRs are excluded from fresh selection unless
+  the operator explicitly requests continuation
+  (`review_proofs.classify_issue_for_selection`,
   `assess_issue_selection_final_report`)
 - queue/inventory tasks: `Repositories checked:`, `Open PR counts:`,
   `Selected PR or reason none selected:`, `Inventory completeness:`