feat(gitea): der Commit-Status verlinkt endlich die Artefaktseite — repo-bezogen

Der letzte offene Punkt der Sitzung D („Gitea status links use the repo-scoped
URLs"). Beim Nachsehen war es kein Scoping-Problem, sondern ein fehlendes
Feature: `server.publicBaseUrl` ist als „used for all links posted to Gitea"
dokumentiert, der Executor postete aber `targetUrl = null` — es gab überhaupt
keinen Link. Jetzt zeigt der Status auf die Artefaktseite des Builds, also auf
die Logs, um die es geht. Ohne `publicBaseUrl` bleibt er null: ein relativer
Link in einem Gitea-Status wäre schlimmer als keiner, er löste gegen die Forge
auf.

Die Präfix-Regel wohnt jetzt an einer Stelle (`RepoLinks`), weil drei
dasselbe damit tun: die Seiten, die API-Antworten und diese Ziel-URLs — und
eine dreimal ausgeschriebene Regel driftet. Die Slice-Tests binden die echte
Komponente per @Import ein, statt die Regel im Test nachzubauen.

Ein neuer Test (mit publicBaseUrl trägt der Status die Artefaktseite; die
vorhandenen Tests halten fest, dass ohne sie weiterhin null gepostet wird).
499 Tests grün, ktlint sauber. Plan und Architektur-Skill nachgezogen.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.claude/skills/architecture/SKILL.md

@@ -67,7 +67,7 @@ Everything repository-scoped goes through a `RepoContext` (`repo` package, ADR 0
 
 ## Build Execution
 
-`BuildExecutor` runs builds asynchronously: `startBuild(repo, branch, commit, build)` takes the `RepoContext` first; up to `executor.maxConcurrent` builds run concurrently across all repositories (default 1, sized once from the first build's config — an instance-level setting), but never more than one build per (repository, branch) at a time. Each branch builds in its own reusable git worktree at `.git/werkator/worktrees/<branchKey>` (`BranchWorkspaces`), checked out detached at the requested commit — the primary checkout is never used for builds. Status transitions are persisted in the build's own `RepoContext.results` (JSON file under that repository's `.git/werkator/`), published to Gitea non-fatally, and emitted as `BuildStatusChangedEvent`s. Every run belongs to a named build definition (job, ADR 0007): the YAML `builds` section defines triggers (`onPush`, `atTimes`), branch selectors (`branches` globs, `activeWithin`), and build-setting overrides applied last over the merged branch config; the implicit `default` build (`onPush`, all branches) preserves the job-less behavior. Definitions are part of the branch layer — a branch may add and override its own, and they apply to that branch alone (its selectors are evaluated for it only) — while `executor.maxConcurrent` stays pinned. `BuildResult.build` records the job; restart, retry, and startup recovery re-run by that name, resolving settings from the *current* config. `BuildResult.name` — the pool, `<branch>@<build>` for non-default builds — keys everything display- and retention-side (repository grouping via `latestPerName`, retention pools, branches-view rows, permanent latest-green links), while `BuildResult.branch` keys everything git-side: origin lookups, gone-from-origin pruning, worktrees (every build runs in its branch's worktree, serialized per branch), and Gitea links/statuses. `branches.*.autoBuild` survives as a deprecated alias for a scheduled default-pool rebuild. Cancellation addresses a build by artifact key and terminates the whole process tree. Future code (watcher, server, UI) must not assume a single running build.
+`BuildExecutor` runs builds asynchronously: `startBuild(repo, branch, commit, build)` takes the `RepoContext` first; up to `executor.maxConcurrent` builds run concurrently across all repositories (default 1, sized once from the first build's config — an instance-level setting), but never more than one build per (repository, branch) at a time. Each branch builds in its own reusable git worktree at `.git/werkator/worktrees/<branchKey>` (`BranchWorkspaces`), checked out detached at the requested commit — the primary checkout is never used for builds. Status transitions are persisted in the build's own `RepoContext.results` (JSON file under that repository's `.git/werkator/`), published to Gitea non-fatally — with the build's artifact page as `target_url` when `server.publicBaseUrl` is set, repository-scoped through `RepoLinks` — and emitted as `BuildStatusChangedEvent`s. Every run belongs to a named build definition (job, ADR 0007): the YAML `builds` section defines triggers (`onPush`, `atTimes`), branch selectors (`branches` globs, `activeWithin`), and build-setting overrides applied last over the merged branch config; the implicit `default` build (`onPush`, all branches) preserves the job-less behavior. Definitions are part of the branch layer — a branch may add and override its own, and they apply to that branch alone (its selectors are evaluated for it only) — while `executor.maxConcurrent` stays pinned. `BuildResult.build` records the job; restart, retry, and startup recovery re-run by that name, resolving settings from the *current* config. `BuildResult.name` — the pool, `<branch>@<build>` for non-default builds — keys everything display- and retention-side (repository grouping via `latestPerName`, retention pools, branches-view rows, permanent latest-green links), while `BuildResult.branch` keys everything git-side: origin lookups, gone-from-origin pruning, worktrees (every build runs in its branch's worktree, serialized per branch), and Gitea links/statuses. `branches.*.autoBuild` survives as a deprecated alias for a scheduled default-pool rebuild. Cancellation addresses a build by artifact key and terminates the whole process tree. Future code (watcher, server, UI) must not assume a single running build.
 
 On context close (e.g. systemd SIGTERM), a `ContextClosedEvent` listener in `BuildExecutor` terminates the process trees of all executing builds and waits (bounded) until their results are persisted as INTERRUPTED — a shutdown is never recorded as FAILED. Builds still queued stay PENDING and start no process. Both are re-enqueued by the watcher's startup recovery; INTERRUPTED therefore publishes as Gitea state `pending`, not `failure` (`GiteaStateMapping`).