docs: receipt evidence keys and carry record fields; carry refusal fix line

Documentation audit for #3564 (/document-release, audit ship3564-docs-1).

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

docs/ship-policy.md

@@ -777,7 +777,8 @@ written by the pr-body section of `/ship` after the body is composed.
 
 The ```` ```gstack-ship-receipt ```` block is the handoff record: identifiers
 first (`pr`, `head`, `version`, `base`), then the evidence (`gate`, `ci`,
-`pregate`, `issues`, `approval`, `docs`, `review_loop`, `carry`), validated
+`head_tree`, `product_patch_id`, `pregate`, `issues`, `approval`, `docs`,
+`review_loop`, `carry`), validated
 against the `ship-receipt` schema (`gstack-artifact schema ship-receipt`) and
 read back by `gstack-ship-receipt read`, `result`, `carry` and the queue.
 
@@ -944,7 +945,9 @@ full rerun because a merge changed its generated index's diff). A base merge
 contributes no product change of its own. A receipt carried twice keeps the reviewed head as
 `carry.from` and adds up the merges and paths. The carried receipt records
 `carry: { from, reason, product_patch_id, changed_paths, merge_commits,
-range_diff, covers, reruns }` with the `git range-diff` evidence, prints
+range_diff, covers, reruns, ancestry, trees }` (`ancestry` is `linear`
+along the receipt's own history, `rewritten` once any hop was a rebase;
+`trees` lists the earlier covered trees) with the `git range-diff` evidence, prints
 `CARRY: carried from <old> to <new> (<reason>)` and the `GSTACK_RESULT:
 skill=ship status=complete` line, and its summary line ends with
 `carried_from=<old12>`. `CARRY: current` means the receipt already names HEAD;

docs/troubleshooting.md

@@ -4734,7 +4734,9 @@ is not the reviewed one. The reviewed verdict does not cover HEAD, so the
 receipt is not carried. The refusal names the changed product paths.
 
 **Fix.** Run /ship on the new head. The receipt carries only across a
-conflict-only base merge, a test-only change or release metadata, which the
+conflict-only base merge, a test-only change, release metadata, a registered
+output the pregate's regen check proved, or a rebase onto a covered tree with
+the recorded product diff, which the
 `carry` object in the carried receipt records with the product patch-id and
 the range-diff evidence ([unattended.md](unattended.md#the-terminal-line)).
 

docs/unattended.md

@@ -225,8 +225,8 @@ and reruns carry with `--pregate .gstack/tmp/pregate.json`. `CARRY: carried from
 now names HEAD with a `carry` object holding the `git range-diff` evidence, and
 `ship-run.json` gains `carried_from` and `carry_reason`; the `review_loop`
 counters are kept, because the reviewed product diff is unchanged. `CARRY:
-current` means nothing moved. `CARRY: refused (RECEIPT_CARRY_PRODUCT_CHANGED)`
-, `(RECEIPT_CARRY_TREE_MISMATCH)` or `(RECEIPT_CARRY_REFUSED)` with the refused
+current` means nothing moved. `CARRY: refused (RECEIPT_CARRY_PRODUCT_CHANGED)`,
+`(RECEIPT_CARRY_TREE_MISMATCH)` or `(RECEIPT_CARRY_REFUSED)` with the refused
 result line means the product diff changed, or history was rewritten onto a
 tree no review saw, so /ship runs again;
 `(RECEIPT_GIT_TOO_OLD)` means the machine's git predates 2.39 and cannot run