fix(ship-receipt): drop the pin-entry guess; stamp-file sides compare ls-tree entries (GST-1210, GSTA-36 ruling A)

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

docs/ship-policy.md

@@ -1506,7 +1506,6 @@ receipt when the base moves:
 | a stacked PR whose receipt was written against the base, after its parent landed and the base was merged in, HEAD's product diff exactly the reviewed range from the parent's head | carries (reason `stack parent <sha12> landed`); base context next to the child's hunks is `RECEIPT_CARRY_SCOPED_REVIEW` |
 | a stamp on the branch's own rows in a stamp file the branch also changed as product: every changed line at a branch-added position, the file's mode unchanged, the base not touching it, the rest of the product diff unchanged | carries (reason `a stamp on the branch's own rows (<file>)`) |
 | a stamp file the branch changes, against each head's base, by no more than a stamp (back at the base's content after a changelog-fragment conversion, or only its version field moved), whatever else the base changed in it | carries (reason `release metadata`, GST-1210) |
-| a one-line `*.json` pin file the branch added, named `…/<key>.json`, whose change since the reviewed head is byte for byte the base's own edit of entry `<key>` in a JSON map line of a base file (a merge that ports a base repin into a one-file-per-entry split) | carries (reason `base entries ported byte for byte (<file>)`, GST-1210); a pin that differs from the base's entry, or sits in another entry's file, refuses |
 
 **Stacked PRs (#3570).** A child PR's receipt is written against its parent
 branch, so its `base` names that branch and its `product_patch_id` is the

docs/troubleshooting.md

@@ -5996,8 +5996,7 @@ landed on the base, a stamp on the branch's own rows in a stamp file it also
 changed as product (every changed line at a branch-added position, the mode
 unchanged, the base not touching the file), a stamp file the branch changes by
 no more than a stamp against each head's base (a changelog-fragment conversion
-that puts `package.json` back at the base's content), a one-entry pin file
-whose change is byte for byte the base's edit of that entry, or base context next to unchanged
+that puts `package.json` back at the base's content), or base context next to unchanged
 hunks after a clean scoped review ([`RECEIPT_CARRY_SCOPED_REVIEW`](#receipt-carry-scoped-review)), 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)).