fix: use write credentials for issue mutations

[chubes4]

Summary

• Route issue create/update/comment/label operations through the issues_write credential capability.
• Keep issue reads on normal repo-selected credentials.

Tests

• php tests/smoke-github-credential-profiles.php
• php tests/smoke-github-create-abilities.php
• php tests/smoke-github-fetch-by-number.php

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (openai/gpt-5.5)
• Used for: Diagnosed the remaining issue-comment 403, drafted the mutation credential routing, and ran focused smoke tests.

[homeboy-ci]

Homeboy Results — data-machine-code

Lint

✅ lint — passed

ℹ️ Full options: homeboy docs commands/lint
ℹ️ Save lint baseline: homeboy lint data-machine-code --baseline
Deep dive: homeboy lint data-machine-code --changed-since e6599bf

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-code-lint-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-code-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-code/actions/runs/26722537805

Test

✅ test — passed

ℹ️ No impacted tests found for --changed-since e6599bf
ℹ️ Run full suite if needed: homeboy test data-machine-code
Deep dive: homeboy test data-machine-code --changed-since e6599bf

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-code-test-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-code-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-code/actions/runs/26722537805

Audit

✅ audit — passed

• audit — 5 finding(s)
• Total: 5 finding(s)

Deep dive: homeboy audit data-machine-code --changed-since e6599bf

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-code-audit-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-code-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-code/actions/runs/26722537805

Tooling versions

• Homeboy CLI: homeboy 0.213.7+4bfb43c
• Extension: wordpress from https://github.com/Extra-Chill/homeboy-extensions
• Extension revision: 88e09a33
• Action: unknown@unknown