Open-source restore: move the source into this repo

The consolidation move itself — single fresh-history commit into this repo. Checklist, in order:

- [x] Prepare the tree: externalize release credentials from conveyor.conf / build files (unquoted HOCON env substitutions; per-user defaults.conf locally); fix the Sentry env-var lookup
- [x] Move the AI scaffolding prompts to docs/prompts/; drop the private/ folder
- [x] Absorb the redisclient harness as testenv/redisclient/; merge the distribution README (drop the closed-source note)
- [x] Add LICENSE, THIRD-PARTY-NOTICES, SECURITY.md (#10) and docs/CONVENTIONS.md
- [x] **Add issue templates in the same push: bug, feature, and new-tool — the new-tool template embeds the docs/CONVENTIONS.md "adding a new tool" checklist**
- [ ] Fresh single-commit history; run a secret scanner over the commit *(tree already scanned CLEAN; orphan commit + final scan happen at publish)*
- [x] Enable secret scanning + push protection first (#9) — *enabled 2026-07-29*
- [ ] Force-push as main *(blocked: waiting on credential rotation)*
- [ ] Delete stale branches (auto-closes PR #7); update the repo description
- [ ] Archive the old development repo

Releases, tags, appcasts, Pages and issues are untouched by this — the update chain for installed 1.1.0 apps keeps working. Ships with #12 as the 1.1.1 proof release.

**Status 2026-07-29:** everything up to the push is done and staged on the private repo's `oss-restore` branch (5 commits: credentials → env/local-include, OSS docs, support-link fix, testenv harness, ktlintFormat). Tree secret-scanned CLEAN; `./gradlew ktlintCheck assemble` green. Remaining steps run after credential rotation.

Start with the checklist and docs/CONVENTIONS.md, then inspect the staged oss-restore branch and its five commits. Run ./gradlew ktlintCheck assemble to confirm the current tree, and treat credential rotation, the fresh-history publish, branch cleanup, repository description, and old-repository archival as the remaining completion criteria.

Written by the indexing model from the issue text.