fix: add OAuth account update helpers

[chubes4]

Summary

• Adds explicit OAuth account update helpers for site, policy-resolved, user, and agent account slots so token refreshes can merge partial data without losing stored fields like scope.
• Keeps existing save_*account*() APIs as full replacement paths for initial auth and re-consent flows.
• Reads exact scoped storage slots during merge updates so user/agent updates do not accidentally inherit site fallback or filter-resolved external credentials.

Fixes #2168.

Testing

• homeboy test --force-hot --path \"/Users/chubes/Developer/data-machine@fix-oauth-account-update-api\" --extension wordpress --output \"/var/folders/lr/c_cmmt7s0592m4njz99v5yb40000gn/T/opencode/data-machine-2168-test.json\"
• git diff --check
• homeboy lint --force-hot --changed-since origin/main --path \"/Users/chubes/Developer/data-machine@fix-oauth-account-update-api\" --extension wordpress --output \"/var/folders/lr/c_cmmt7s0592m4njz99v5yb40000gn/T/opencode/data-machine-2168-lint.json\"

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Drafted the code changes and tests under Chris's direction; 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 6e0835c

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/26300679466

Test

✅ test — passed

• 114 passed

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 6e0835c

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/26300679466

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 6e0835c

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/26300679466

Tooling versions

• Homeboy CLI: homeboy 0.197.2+b55fc5e9
• Extension: wordpress from https://github.com/Extra-Chill/homeboy-extensions
• Extension revision: dd23ee80
• Action: unknown@unknown