fix(git-wrappers): #865 round-7 addendum — conservative YAML recognizer + review/comment hardening

Fold the remaining round-7 audit items into the tea-CLI comment-invocation fix.

Fallback token parser (detect-platform.sh, test-gitea-login-resolution.sh):
Replace the line-by-line scalar fallback with a strict CONSERVATIVE block-YAML
recognizer that reconstructs the same object PyYAML would or fails closed the
instant it meets anything outside the tea-config subset. Closes 5 structural
fail-open classes the old parser missed (nested-shadow logins, block-scalar
shadow, duplicate root key / login name / token field, malformed-after-valid,
extra-document / end-marker). Validated by a 360k-check differential fuzz vs
real PyYAML (0 fail-open) plus explicit forced-PyYAML-absence fixtures.

ITEM 1 (pr-review.sh) current-head TOCTOU: after the exact review-id read-back
succeeds, re-read the live PR head and fail closed if it advanced past the
submitted commit_id, so a review is never reported as covering a superseded tip.

ITEM 2 (pr-review.sh comment action): require the returned resource be a
pull_request (populated pull_request_url); reject a bare issue_url so a plain
issue #N cannot masquerade as a verified PR comment. issue-comment.sh keeps its
broader issue-or-PR acceptance.

ITEM 3a (both wrappers): move the Authorization bearer OUT of curl argv into a
private mode-0600 curl --config file (gitea_write_auth_config), removed on every
exit path, so the token never appears in the process table.

ITEM 3b (pr-review.sh): bind the review body with presence + string-type + exact
equality instead of `(body or "")`, so a non-empty submitted body persisted as
null/missing fails closed.

Tests: add race, plain-issue, argv-capture (no token printed), and null-body
fixtures; broaden temp-leak checks to the auth-config files. Full gate set green
(bash -n, shellcheck -x -S warning, prettier, all 3 REST/resolution suites with
PyYAML and forced-absent, cold TURBO_FORCE turbo 14/14).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

packages/mosaic/framework/tools/git/test-gitea-login-resolution.sh

@@ -477,4 +477,148 @@ write_fixture "logins:
 "
 assert_token "single-quoted token is a literal string" "abc" primary git.example
 
+# assert_fallback_fails_closed: the forced-fallback path MUST resolve no token
+# (fail closed). Used for STRUCTURAL cases where PyYAML would resolve a DIFFERENT
+# token (e.g. duplicate-key last-wins) — the fallback must never surface the
+# wrong/stale token, so it fails closed instead; when PyYAML is present we also
+# confirm it really does resolve a (divergent) token, proving the fallback is the
+# strictly-more-conservative side and the case is a genuine fail-open guard.
+assert_fallback_fails_closed() {
+    local desc="$1" login="$2" host="$3" got
+    got=$(token_fallback "$login" "$host")
+    if [[ -n "$got" ]]; then
+        echo "FAIL fallback [$desc]: expected fail-closed, got a token" >&2
+        exit 1
+    fi
+    if [[ "$HAVE_PYYAML" == true ]]; then
+        got=$(token_pyyaml "$login" "$host")
+        if [[ -z "$got" ]]; then
+            echo "FAIL [$desc]: expected PyYAML to resolve a divergent token" >&2
+            exit 1
+        fi
+    fi
+}
+
+# 10. tea's REAL on-disk shape: the `logins:` block SEQUENCE items sit at the
+#     SAME indentation as the key (dash at column 0), with extra scalar fields.
+#     The recognizer must resolve this exactly like PyYAML (regression guard so
+#     the stricter whole-document recognizer does not fail closed on real input).
+write_fixture 'logins:
+- name: primary
+  url: https://git.example
+  token: TOK_REAL
+  default: false
+  ssh_host: ""
+- name: other
+  url: https://other.example
+  token: TOK_REAL_OTHER
+preferences:
+  editor: false
+  flags: null
+'
+assert_token "tea dash-at-column-0 real shape resolves" "TOK_REAL" primary git.example
+assert_token "tea real shape sibling resolves own token" "TOK_REAL_OTHER" other other.example
+
+# 11. NESTED-SHADOW: a nested `logins:` (NOT at root scope) must not be mistaken
+#     for the real root logins. The recognizer parses whole-document structure,
+#     so it selects the ROOT logins token exactly as PyYAML does — never the
+#     nested attacker token. (A prior line scan matched the FIRST logins at ANY
+#     indent and returned ATTACKER.)
+write_fixture 'outer:
+  logins:
+    - name: primary
+      url: https://git.example
+      token: ATTACKER_NESTED
+logins:
+  - name: primary
+    url: https://git.example
+    token: ROOT_TOK
+'
+assert_token "nested logins shadow selects ROOT token" "ROOT_TOK" primary git.example
+
+# 12. BLOCK-SCALAR-SHADOW: text inside a YAML literal/folded block ( | or > ) is
+#     an OPAQUE scalar to PyYAML (so `logins` is a string, not a list) and must
+#     not be scanned as live logins entries. Both fail closed.
+write_fixture 'logins: |
+  - name: primary
+    url: https://git.example
+    token: ATTACKER_BLOCK
+'
+assert_token "block-scalar logins value fails closed" "" primary git.example
+# A folded/literal block scalar anywhere is outside the recognizer's subset, so
+# the fallback fails closed (conservative) even though PyYAML can still resolve
+# the real root token past the opaque scalar. Fail-closed is the safe side.
+write_fixture 'note: >
+  logins:
+    - name: primary
+      token: ATTACKER_FOLDED
+logins:
+  - name: primary
+    url: https://git.example
+    token: ROOT_OK
+'
+assert_fallback_fails_closed "folded block scalar present fails closed" primary git.example
+
+# 13. DUPLICATE-ROOT / DUPLICATE-FIELD: a duplicated `logins:` root key (PyYAML
+#     last-wins) or a duplicated field within a login must fail closed rather
+#     than take the FIRST (stale) value. PyYAML resolves the LAST; the fallback
+#     refuses to guess.
+write_fixture 'logins:
+  - name: primary
+    url: https://git.example
+    token: FIRST_DUP
+logins:
+  - name: primary
+    url: https://git.example
+    token: LAST_DUP
+'
+assert_fallback_fails_closed "duplicate root logins key fails closed" primary git.example
+write_fixture 'logins:
+  - name: primary
+    url: https://git.example
+    token: FIRST_FIELD
+    token: SECOND_FIELD
+'
+assert_fallback_fails_closed "duplicate token field fails closed" primary git.example
+
+# 14. MALFORMED-AFTER-VALID: a syntax error LATER in the file makes PyYAML reject
+#     the WHOLE document; the recognizer must too (not emit the earlier token).
+write_fixture 'logins:
+  - name: primary
+    url: https://git.example
+    token: TOK_PLAIN
+broken: a: b: c
+'
+assert_token "malformed line after valid login fails closed" "" primary git.example
+write_fixture 'logins:
+  - name: primary
+    url: https://git.example
+    token: TOK_PLAIN
+broken: [unclosed
+'
+assert_token "unclosed flow after valid login fails closed" "" primary git.example
+
+# 15. EXTRA-DOCUMENT: a multi-document file (--- separator, or ... end marker)
+#     makes PyYAML safe_load reject multi-document input; the recognizer fails
+#     closed on ANY document marker rather than emit the first doc's token.
+write_fixture 'logins:
+  - name: primary
+    url: https://git.example
+    token: TOK_PLAIN
+---
+logins:
+  - name: primary
+    url: https://git.example
+    token: SECOND_DOC
+'
+assert_token "second document (--- separator) fails closed" "" primary git.example
+write_fixture 'logins:
+  - name: primary
+    url: https://git.example
+    token: TOK_PLAIN
+...
+trailing: 1
+'
+assert_token "end marker then more content fails closed" "" primary git.example
+
 echo "Gitea login resolution regression harness passed"