t27b coverage: real tests for 9 function cards in specs/functions (morph to ton) #8283

Part of #6063 (t27b coverage), which is item C10 of #6488 ("coverage counted without vacuous passes").

What is wrong

On the t27b lab, 18 function cards of specs/functions pass vacuously (0 runtime asserts) under the reference and t27b: they have no test, invariant or bench block, which also breaks L4 TESTABILITY. This issue covers the other 9 in file order: morph-images-generate, neuro-image-generate, payment-ai-server-process, reels-ai-callback, reels-ai-generate, reels-loop-generate, render-avatar-video-run, robokassa-unclaimed-watch, ton-pending-watch.

What the tests check

specs/functions/README.md states the schema of a function card and the rules its generator enforces. The tests hold each card to them:

1. ID is <domain>-<object>-<verb>, with DOMAIN from the README's vocabulary as its first part.
2. TRIGGER decides the rest. An event function has an EVENT and CRON = "", and its canonical EVENT names the same three parts as ID (<domain>/<object>.<verb>). A cron function has a five-field CRON, EVENT = "" and no LEGACY_EVENTS.
3. ON_FAILURE, PROBE_RESULT, CONTROL and every SIDE_EFFECTS value come from their vocabularies; no side effect is listed twice. KIND, REPO and TZ are as the schema states.
4. SAFE_PROBE agrees with PROBE_RESULT. "" means no probe was sent (skipped, or not-deployed with GUARD = unknown). A JSON object means the probe reached the function (COMPLETED, or FAILED-at-guard with a named GUARD).
5. SERVICE is file:line.

Cards that break rule 1 (see #7911) keep rules 2 to 5 and skip rule 1.

Earlier attempt

See #6890: an open PR of an earlier attempt that adds tests to 7 of these 9 cards. Its tests restate each constant, which this lane rules out; it is superseded, not built on.

Done when

• each card has these tests, passing under the reference (t27c test-report, 0 vacuous) and under t27b;
• each is sealed;
• the ledger rows that move come from bless of the branch run;
• the signed lane receipts compare as IMPROVED_ONLY.

User Scenarios

• Given the 9 function cards in specs/functions lack test, invariant, or bench blocks, When t27c test-report runs, Then each card passes vacuously with 0 runtime asserts
• Given tests are added to each of the 9 cards per the schema rules in specs/functions/README.md, When t27c test-report and t27b run, Then all 9 cards pass with non-vacuous asserts under both runners
• Given all tests pass non-vacuously, When the branch is blessed and lane receipts are compared, Then ledger rows move from the bless run and receipts show IMPROVED_ONLY

Requirements

• FR-001: Each of the 9 function cards MUST have at least one test, invariant, or bench block with runtime asserts
• FR-002: Tests MUST verify ID follows <domain>-<object>-<verb> with DOMAIN from specs/functions/README.md vocabulary (cards noted in Five cards break their directory's schema, two carry non-ASCII (found by the #6063 test lane) #7911 exempt rule 1 only)
• FR-003: Tests MUST verify TRIGGER rules: event functions have EVENT matching <domain>/<object>.<verb> and empty CRON; cron functions have five-field CRON, empty EVENT, and no LEGACY_EVENTS
• FR-004: Tests MUST verify ON_FAILURE, PROBE_RESULT, CONTROL, and every SIDE_EFFECTS value come from their declared vocabularies with no duplicate side effects
• FR-005: Tests MUST verify KIND, REPO, and TZ conform to the schema in specs/functions/README.md
• FR-006: Tests MUST verify SAFE_PROBE agrees with PROBE_RESULT per specification (empty means no probe sent; JSON object means probe reached function)
• FR-007: Tests MUST verify SERVICE is file:line format
• FR-008: All 9 cards MUST pass under t27c test-report with 0 vacuous passes
• FR-009: All 9 cards MUST pass under t27b with 0 vacuous passes
• FR-010: Each card MUST be sealed after tests pass
• FR-011: Ledger rows that change MUST originate from bless of the branch run
• FR-012: Signed lane receipts MUST compare as IMPROVED_ONLY

Boundary

• specs/functions/morph-images-generate.t27
• specs/functions/neuro-image-generate.t27
• specs/functions/payment-ai-server-process.t27
• specs/functions/reels-ai-callback.t27
• specs/functions/reels-ai-generate.t27
• specs/functions/reels-loop-generate.t27
• specs/functions/render-avatar-video-run.t27
• specs/functions/robokassa-unclaimed-watch.t27
• specs/functions/ton-pending-watch.t27
• specs/functions/README.md