feat(release): add public registration polish gates

[JSONbored]

Summary

• quiet the GitHub App public surface so only officially confirmed Gittensor miner PRs get public comments/labels
• add public-registration polish for docs, support, security posture, changelogs, release gates, and MCP package metadata
• add repo-owner registration readiness and Gittensor config recommendation APIs

What changed

• added sanitized comment/label defaults and tests for confirmed-miner-only GitHub App behavior
• added full AGPL license text, SUPPORT.md, privacy/terms/support docs pages, and updated public-facing wording
• added root and MCP changelogs with split git-cliff configs and changelog:check
• hardened CI with whitespace, actionlint, docs, changelog, package dry-run, and audit gates
• bumped @jsonbored/gittensory-mcp to 0.1.4 with packaged CHANGELOG.md and a changelog CLI command
• added registration-readiness and Gittensor-config recommendation endpoints plus OpenAPI/tests

Why

Gittensory is public now, and the remaining blocker before Gittensor registration is polish: public text needs to match the current product behavior, the GitHub App needs to avoid noisy/private-signal leaks, package releases need a real changelog path, and repo owners need machine-readable registration-readiness guidance.

Validation

• npm run test:ci
• node packages/gittensory-mcp/bin/gittensory-mcp.js changelog --json
• GITTENSORY_SKIP_NPM_VERSION_CHECK=true node packages/gittensory-mcp/bin/gittensory-mcp.js status --json
• npm view @jsonbored/gittensory-mcp version

Local gate result: 198 tests passed, branch coverage is 90.02%, MCP package dry-run passed, docs build passed, changelog check passed, and npm audit found no vulnerabilities.

Notes

• @jsonbored/gittensory-mcp@0.1.4 is prepared but not published by this PR. Publish after merge with the protected mcp-v0.1.4 tag path.
• The branch coverage gate remains at 90%. Raising it to 92% needs a separate coverage-focused pass; the current suite is barely above 90% by design.