t27b checked: test blocks for 7 specs in specs/crons (6 of 8)

Refs #6063 (t27b coverage epic). Filed by the bee feed (lab run 682564f48, https://t27b-lab-production.up.railway.app/latest.json).

The Railway t27b lab says the reference path (t27c gen + zig test) passes each spec below, and t27b compiles each one too -- but each is pass_vacuous: it has no test block, so nothing is checked at runtime and it does not count toward t27b coverage. One test block per spec that asserts what the spec already declares makes it a checked pass the next time the lab runs.

• specs/crons/mac-trios-cycle.t27
• specs/crons/mac-trios-doctor.t27
• specs/crons/mac-trios-feed.t27
• specs/crons/mac-trios-heal.t27
• specs/crons/railway-jobsearch-cron.t27
• specs/crons/t27-formal-mutation.t27
• specs/crons/t27-pr-dashboard.t27

Out of bounds (do not edit): any other file, seals under .trinity/seals/, docs/reports/, gen/, and the blog progress spec. The steward re-blesses the t27b ledger after the lab sees the change.

Boundary

specs/crons/mac-trios-cycle.t27
specs/crons/mac-trios-doctor.t27
specs/crons/mac-trios-feed.t27
specs/crons/mac-trios-heal.t27
specs/crons/railway-jobsearch-cron.t27
specs/crons/t27-formal-mutation.t27
specs/crons/t27-pr-dashboard.t27

User Scenarios & Testing

• Given each spec above has no test block and t27c test-report <spec> prints tests 0,
  when one test block is appended to each spec and the commands under Success Criteria are run from the repository root,
  then each command prints the value stated beside it, and the next t27b lab run counts these specs as checked passes instead of pass_vacuous.

Requirements

• FR-001: append exactly one test <snake_case_name> { ... } block at the end of each spec listed above (before endmodule if the file has one). Do not change, reorder or remove any existing line; the number of pub const lines stays the same.
• FR-002: each test MUST hold at least 4 assert lines, each on its own line, comparing a constant the spec declares with the literal value it declares: assert KIND == "cron";, assert ENABLED == true;, assert ORDER == 4;, a bound such as assert INTERVAL_MS >= 60000;, or one element of a fixed array such as assert TAGS[0] == "corpus";. Use only ==, !=, <, <=, >, >= on str, bool and integer constants. No assert true, no new functions, no new constants, no imports.
• FR-003: every assert MUST hold: t27c test-report <spec> prints FAIL 0 and a pass count of 1 or more. A failing assert means the value was copied wrong -- fix the assert, never the constant.
• FR-004: the files MUST stay ASCII-only (law L3).
• FR-005: the PR contains only .t27 files (the specs above) and nothing hand-written in any other language, no generated file, no scratch file, no docs/now/ entry written by hand.
• FR-006: If this work raises the number of specs t27b passes with runtime checks, write t27b-blog: +N <spec paths> in the PR body, so the daily blog entry can name which bee work moved the number.

Success Criteria

• 1. t27c test-report specs/crons/mac-trios-cycle.t27 2>&1 | grep -cE '^ (FAIL +0|pass +[1-9][0-9]*)$' prints 2 (today it prints 1: tests 0, nothing runs)
• 2. grep -cE '^[[:space:]]+assert' specs/crons/mac-trios-cycle.t27 prints at least 4
• 3. t27c test-report specs/crons/mac-trios-doctor.t27 2>&1 | grep -cE '^ (FAIL +0|pass +[1-9][0-9]*)$' prints 2 (today it prints 1: tests 0, nothing runs)
• 4. grep -cE '^[[:space:]]+assert' specs/crons/mac-trios-doctor.t27 prints at least 4
• 5. t27c test-report specs/crons/mac-trios-feed.t27 2>&1 | grep -cE '^ (FAIL +0|pass +[1-9][0-9]*)$' prints 2 (today it prints 1: tests 0, nothing runs)
• 6. grep -cE '^[[:space:]]+assert' specs/crons/mac-trios-feed.t27 prints at least 4
• 7. t27c test-report specs/crons/mac-trios-heal.t27 2>&1 | grep -cE '^ (FAIL +0|pass +[1-9][0-9]*)$' prints 2 (today it prints 1: tests 0, nothing runs)
• 8. grep -cE '^[[:space:]]+assert' specs/crons/mac-trios-heal.t27 prints at least 4
• 9. t27c test-report specs/crons/railway-jobsearch-cron.t27 2>&1 | grep -cE '^ (FAIL +0|pass +[1-9][0-9]*)$' prints 2 (today it prints 1: tests 0, nothing runs)
• 10. grep -cE '^[[:space:]]+assert' specs/crons/railway-jobsearch-cron.t27 prints at least 4
• 11. t27c test-report specs/crons/t27-formal-mutation.t27 2>&1 | grep -cE '^ (FAIL +0|pass +[1-9][0-9]*)$' prints 2 (today it prints 1: tests 0, nothing runs)
• 12. grep -cE '^[[:space:]]+assert' specs/crons/t27-formal-mutation.t27 prints at least 4
• 13. t27c test-report specs/crons/t27-pr-dashboard.t27 2>&1 | grep -cE '^ (FAIL +0|pass +[1-9][0-9]*)$' prints 2 (today it prints 1: tests 0, nothing runs)
• 14. grep -cE '^[[:space:]]+assert' specs/crons/t27-pr-dashboard.t27 prints at least 4