ci: give test:tech-log its own gate command and junit evidence

The TechLog suite already ran in CI, but only inside `test:coverage`'s combined
`vitest run tests/runtime-schema tests/unit … tests/features/tech-log`
invocation on FE-GATE-005. A TechLog regression therefore surfaced as a
coverage-gate failure, and the only junit that carried it was coverage.xml,
which reports every other suite at the same time.

`test-tech-log` now sits on FE-GATE-007 beside `test-reference-feature`, the
sibling it mirrors — both drive a suite under `tests/features/` — and declares
`artifacts/tests/tech-log.xml`, which `test:tech-log` already wrote, as its own
command-generated junit evidence. The gate log now names
`$ corepack pnpm test:tech-log` as its own step and the failure lands on the
suite that produced it.

Adding a command and an artifact moves the exact-count authority to 84
definitions / 96 references / 130 artifacts (109 evidence references), and
changes the canonical gate shape digest because FE-GATE-007's commandIds and
evidenceArtifactIds are part of it. There is no tooling to regenerate that
digest, so it was recomputed by hand under the standing procedure: a fresh
transcription of `canonicalGateShapeSha256` first reproduced the committed
f3cc9075… from the unedited config/ci/gates.json — proving the transcription,
not just agreeing with whatever the check compares against — and only then
hashed the edited file to 98d19911….

`corepack pnpm ci:gate -- FE-GATE-007` passes end to end; the generated
workflow bytes are unchanged, since the yml dispatches gates rather than
commands.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

config/ci/gates.json

@@ -174,6 +174,11 @@
       "script": "test:reference-feature",
       "expect": "pass"
     },
+    {
+      "id": "test-tech-log",
+      "script": "test:tech-log",
+      "expect": "pass"
+    },
     {
       "id": "test-recipes",
       "script": "test:recipes",
@@ -901,6 +906,15 @@
         "test-reference-feature"
       ]
     },
+    {
+      "id": "artifact-artifacts-tests-tech-log-xml",
+      "path": "artifacts/tests/tech-log.xml",
+      "schemaId": "junit",
+      "production": "command-generated",
+      "producerCommandIds": [
+        "test-tech-log"
+      ]
+    },
     {
       "id": "artifact-artifacts-tests-optional-recipes-xml",
       "path": "artifacts/tests/optional-recipes.xml",
@@ -1852,6 +1866,7 @@
         "test-integration",
         "test-http-scenario-evidence",
         "test-reference-feature",
+        "test-tech-log",
         "test-recipes"
       ],
       "logArtifactId": "artifact-artifacts-quality-gates-FE-GATE-007-txt",
@@ -1861,6 +1876,7 @@
         "artifact-artifacts-quality-http-scenario-evidence-json",
         "artifact-artifacts-quality-http-scenario-evidence-fixture-json",
         "artifact-artifacts-tests-reference-feature-xml",
+        "artifact-artifacts-tests-tech-log-xml",
         "artifact-artifacts-tests-optional-recipes-xml"
       ],
       "retentionClassId": "merge-cycle"