feat: add flow config pre-save filter

[chubes4]

Summary

• Add datamachine_flow_config_pre_save at the flow write boundary for create_flow() and update_flow().
• Allow platform filters to coerce the decoded flow_config array or reject the save with WP_Error before JSON persistence.
• Add a pure-PHP smoke test covering create/update coercion, flow ID/payload arguments, and rejection logging/no-write behavior.

Fixes #2153

Verification

• php tests/flow-config-pre-save-filter-smoke.php
• git diff --check
• homeboy lint --force-hot --changed-since origin/main --path /Users/chubes/Developer/data-machine@fix-flow-config-pre-save-filter --extension wordpress --output /var/folders/lr/c_cmmt7s0592m4njz99v5yb40000gn/T/opencode/data-machine-2153-lint.json

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Drafted the filter implementation, smoke coverage, verification commands, and PR description for Chris to review.

[homeboy-ci]

Homeboy Results — data-machine

Lint

✅ lint — passed

ℹ️ Full options: homeboy docs commands/lint
Deep dive: homeboy lint data-machine --changed-since 935dd38

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/26299405115

Test

✅ test — passed

ℹ️ Auto-fix lint issues: homeboy refactor data-machine --from lint --write
ℹ️ Collect coverage: homeboy test data-machine --coverage
ℹ️ Pass args to test runner: homeboy test -- [args]
ℹ️ Full options: homeboy docs commands/test
Deep dive: homeboy test data-machine --changed-since 935dd38

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/26299405115

Audit

✅ audit — passed

• requested_detectors — 63 finding(s)
• dead_code — 61 finding(s)
• intra-method-duplication — 36 finding(s)
• dead_guard — 8 finding(s)
• parallel-implementation — 7 finding(s)
• repeated_literal_shape — 6 finding(s)
• Flows — 5 finding(s)
• structural — 5 finding(s)
• Flow — 4 finding(s)
• Tools — 3 finding(s)
• Total: 201 finding(s)

Deep dive: homeboy audit data-machine --changed-since 935dd38

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/26299405115

Tooling versions

• Homeboy CLI: homeboy 0.197.2+00d7b92f
• Extension: wordpress from https://github.com/Extra-Chill/homeboy-extensions
• Extension revision: dd23ee80
• Action: unknown@unknown