docs(adr): supersede ADR-0007, plan OneDev migration

This repo's own hosting, issue tracking, and pull requests move from Gitea
to OneDev (ADR-0029), keeping the Gitea repo as a read-only archive rather
than deleting it. plugins/gitea is unaffected — it continues to ship as a
marketplace product regardless of what this repo hosts itself on.

Records the full execution plan (prerequisites, mirror/issue/PR/release
phases, verification checklist) and updates CONTEXT.md's Issue entry and
AGENTS.md's source-of-truth line to name OneDev instead of Gitea.

ADR: 0029
Refs: ADR-0007
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GGCPJBXPLJP5FprL4C8nu3

docs/adr/0007-gitea-canonical-issue-tracker.md

@@ -1,5 +1,7 @@
 # Gitea is the exclusive issue tracker — file-based fallback removed
 
+**Superseded by:** ADR-0029 (OneDev supersedes Gitea as this repo's canonical forge — this repo's own hosting, issue tracking, and PRs move to OneDev; `gitea/` continues to ship as a marketplace product regardless)
+
 **Supersedes:** ADR-0011 (provider-agnostic issue tracker with file-based default — archived during refactoring)
 
 > **Note on the ADR-0011 number.** Every "ADR-0011" on this page means the *archived* provider-agnostic issue tracker ADR, which no longer exists in `docs/adr/` — it was removed when it was superseded, and the number 0011 was later reused for an unrelated decision, `docs/adr/0011-gitea-skill-deep-modules.md` (the gitea skill's split into deep modules). That file is not the ADR referenced below. The number is not renumbered here: these ADRs are a published record and renumbering would break every citation that already points at either one. The archived text is recoverable from git history.

docs/adr/0029-onedev-supersedes-gitea-canonical-forge.md

@@ -0,0 +1,43 @@
+# OneDev supersedes Gitea as this repo's canonical forge
+
+**Supersedes:** ADR-0007 (Gitea as the exclusive issue tracker)
+
+This repo's own hosting, issue tracking, and pull requests move from Gitea (`git.dev.rkdr.net`) to
+OneDev (`onedev.dev.rkdr.net/Holocron`). Gitea is frozen and kept reachable read-only as a historical
+archive rather than deleted, so commit messages, branch names, and ADRs that cite Gitea issue/PR
+numbers (e.g. `#124`, `#140`) stay resolvable. `plugins/gitea/` is unaffected — it continues to ship
+as a marketplace product for consumers with Gitea repos of their own; this decision is about what
+*this* repo uses on itself, not what this repo authors and distributes.
+
+## Considered and rejected
+
+- **Preserving Gitea's issue/PR numbers in OneDev.** Rejected: OneDev issues and pull requests use
+  independent per-type counters, unlike Gitea's single shared sequence — there is no API path to
+  reproduce both simultaneously without a fragile create/delete padding hack. Migrated issues carry a
+  back-link to their original Gitea URL instead; new work uses OneDev's own numbers from the cutover
+  point forward.
+- **Recreating historical PR objects (title/description/reviews) in OneDev.** Rejected for the
+  existing ~140 closed/merged PRs: `tod pr create` requires a live source branch, and Gitea already
+  deletes head branches on merge, so recreating them means resurrecting deleted branches from
+  merge-commit parent SHAs, opening throwaway PRs, and discarding them without merging (to avoid a
+  second, divergent merge commit alongside the mirrored git history). The git mirror already carries
+  every commit, message, author, and merge losslessly; the archived Gitea instance still holds the
+  original PR/review UI for anyone who needs it. Any PRs genuinely open and in flight at cutover time
+  are migrated for real, not archived.
+- **Recreating Gitea's `Reviewed/*`, `Status/*`, and `Compat/Breaking` labels as new OneDev labels.**
+  Rejected in favor of OneDev's own out-of-the-box shape: structured `Type`/`Priority` fields (which
+  `Kind/*` and `Priority/*` map onto directly) plus the native three-state workflow (`Open` /
+  `In Progress` / `Closed`, no built-in disposition states). Disposition information that has no
+  native home becomes a one-line note in the migrated issue body instead of a second, parallel,
+  unstructured label taxonomy next to the real fields.
+
+## Consequences
+
+- Gitea issue/PR numbers cited in existing commit messages and docs remain valid only as long as the
+  archived Gitea instance stays reachable; they are not remapped to OneDev numbers anywhere.
+- The six first-party `apm.yml` plugin dependencies (`git`, `gitea`, `kyberforge`, `lint`, `core`,
+  `bin`), previously resolved unpinned against `git@git.dev.rkdr.net:Defame1297/holocron.git`, are
+  repointed to the OneDev remote as part of this migration — apm's own dependency resolution must
+  track the now-canonical remote, not a frozen archive.
+- `AGENTS.md`'s "this repo and Gitea are the only source of truth" language is updated to name
+  OneDev.