fix: require canonical chat session creation path

[chubes4]

Summary

• Makes datamachine/create-chat-session the single canonical session-creation path for ChatOrchestrator.
• Removes the direct conversation-store fallback so missing ability registration fails loudly.
• Adds source smoke coverage that verifies the canonical ability path and missing-dependency error remain in place.

Fixes #2219.

Verification

• php tests/chat-session-canonical-path-smoke.php
• php -l inc/Api/Chat/ChatOrchestrator.php
• php -l tests/chat-session-canonical-path-smoke.php
• composer exec phpcs -- inc/Api/Chat/ChatOrchestrator.php tests/chat-session-canonical-path-smoke.php
• homeboy test --path /Users/chubes/Developer/data-machine@fix-chat-session-canonical-create --extension wordpress

Verification gaps

• homeboy lint --path /Users/chubes/Developer/data-machine@fix-chat-session-canonical-create --extension wordpress reports existing unrelated JS/admin lint findings outside the touched files.

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Implemented the canonical chat session creation path change, added focused smoke coverage, and ran verification; Chris remains responsible for review and merge.

[homeboy-ci]

Homeboy Results — data-machine

Lint

✅ lint — passed

ℹ️ Full options: homeboy docs commands/lint
Deep dive: homeboy lint data-machine --changed-since cd06f9c

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-lint-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-lint-quality-Linux-node24 contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/data-machine/actions/runs/26350274483

Test

✅ test — passed

• 1152 passed
• 3 skipped

ℹ️ Auto-fix lint issues: homeboy refactor data-machine --from lint --write
ℹ️ Collect coverage: homeboy test data-machine --coverage
ℹ️ Save test baseline: homeboy test data-machine --baseline
ℹ️ Pass args to test runner: homeboy test -- [args]
ℹ️ Full options: homeboy docs commands/test
Deep dive: homeboy test data-machine --changed-since cd06f9c

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-test-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-test-quality-Linux-node24 contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/data-machine/actions/runs/26350274483

Audit

✅ audit — passed

• requested_detectors — 8 finding(s)
• intra-method-duplication — 7 finding(s)
• dead_code — 3 finding(s)
• Directives — 1 finding(s)
• Retention — 1 finding(s)
• Total: 20 finding(s)

Deep dive: homeboy audit data-machine --changed-since cd06f9c

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-audit-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-audit-quality-Linux-node24 contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/data-machine/actions/runs/26350274483

Tooling versions

• Homeboy CLI: homeboy 0.197.3+0415aa2c
• Extension: wordpress from https://github.com/Extra-Chill/homeboy-extensions
• Extension revision: dd23ee80
• Action: unknown@unknown