seals: reseal specs/policy/own_language.t27 after #10201 (coverage red on master) #10210

Goal

Turn the coverage check ("Every seal still describes its spec") on master green again. #10201 changed specs/policy/own_language.t27 and did not reseal it, so tools/check_seal_coverage.py fails on master 27efeba and on every open PR: policy_PolicyOwnLanguage.json [stale] specs/policy/own_language.t27 changed since sealing. Seen on #10185 (epic #10024).

Boundary

• Only .trinity/seals/policy_PolicyOwnLanguage.json changes. It is tool-written seal data, written by t27c seal specs/policy/own_language.t27 --save.
• The spec, its generated C (gen/c/policy/own_language.c), lefthook.yml and the own-language workflow are the gate's protected paths, and none of them is touched.
• No entry is added to seal_baseline.txt. The seal is renewed, not declared as debt.

Scenarios

• Given master 27efeba plus the change, When python3 tools/check_seal_coverage.py runs, Then it exits 0.
• Given the resealed file, When it is compared with the spec on master, Then its spec_hash is the hash of the current specs/policy/own_language.t27 and its test counts are the spec's 36 of 36.

Requirements

• FR-001: The seal MUST be produced by a t27c built from master 27efeba, on the Railway lab.
• FR-002: The PR MUST change exactly one file, .trinity/seals/policy_PolicyOwnLanguage.json.
• FR-003: seal_baseline.txt MUST NOT change.

Success Criteria

• python3 tools/check_seal_coverage.py exits 0 with "OK: 2512 seals" on master plus the change.
• git diff --stat origin/master on the PR branch lists one file.

Close criteria

• The PR merges and the coverage check is green on it.