fix(gitea): admins could override the gate -- the enforcement was not enforcing

enable_status_check and required_approvals were set earlier today and recorded as done.
They did not bite. block_admin_merge_override was false, and Gitea lets repo admins
override merge requirements without it. jakman85 holds owner, so both requirements were
bypassable by exactly the account that performs every merge.

The evidence was already on the record: PRs #5-#9 all merged while required_approvals: 1
was in force, with ZERO approvals recorded on any of them.

Two process failures, both the same shape as the defect this whole session started with:

1. Verified with the wrong view. /branches/main reports protected, enable_status_check and
   required_approvals but NOT block_admin_merge_override -- it showed everything green while
   the rule was overridable. /branch_protections/main is authoritative.
2. Probed for a field name assumed to exist. This Gitea (1.24.3) has no `apply_to_admins`;
   asking jq for it returns null, which reads like "set to false" but means "key absent", so
   a PATCH that silently did nothing produced a convincing before/after. jq returning null
   is not a value -- it may be an absence. Enumerate with to_entries.

require-gate.sh now sets block_admin_merge_override: true; block-admin-override.sh fixes it
in isolation. Both carry the field-name warning.

This PR is the test. If it merges WITHOUT an approval, the fix did not work.

Also records the governance question: with only jakman85 (human) and gitea-admin (agent),
a human-authored PR now needs the automation account to approve it. That is ceremony, not
review, and the choice between keeping it, dropping approvals in favour of the status
check, or adding a second human is the operator's to make.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

infra/gitea/README.md

@@ -55,8 +55,27 @@ All four steps are complete and each was verified, not assumed:
 | 4. Collaborator + approvals | ✅ `jakman85` is owner; `required_approvals: 1` |
 
 Direct push to `main` was **provoked and rejected** (`pre-receive hook declined`) as
-`gitea-admin`, a site admin — so protection is not merely declared, it holds for the account
-agents authenticate as.
+`gitea-admin`, a site admin — so push protection is not merely declared, it holds for the
+account agents authenticate as.
+
+### 5. Block the admin override — the step the first pass MISSED
+
+`enable_status_check` and `required_approvals` were set on 2026-09-29 and **still did not
+bite**, because `block_admin_merge_override` was `false`. Gitea lets repo admins override
+merge requirements without it, and `jakman85` holds `owner` — so the two settings that looked
+like the gate were overridable by precisely the account that merges.
+
+**The evidence was sitting in plain sight:** PRs #5 through #9 all merged with
+`required_approvals: 1` in force and **zero approvals recorded on any of them**. Checking the
+*branch* view (`/branches/main`) hid this — it does not expose the field. Read the rule object
+(`/branch_protections/main`) and enumerate its keys.
+
+> **Do not probe for field names you assume exist.** This Gitea (1.24.3) has no
+> `apply_to_admins`; asking `jq` for it returns `null`, which reads like "set to false" but
+> means "key absent". Enumerate with `to_entries` and act on what is really there.
+
+Now `block_admin_merge_override: true`. **That is still only a setting, not evidence** — it is
+proven when a green PR is REFUSED a merge until approved, and not before.
 
 ### `require-gate.sh` / `verify-then-enforce.sh`