fix(gitea): make gitea-releases executable and correct misleading domain claims

gitea-releases was the weakest skill in the plugin: no allowed-tools, no
owner/repo resolution, and a checkbox list where a dispatch table belongs, so
an agent reaching it had to guess both its permissions and its inputs. The
id-vs-tag_name trap — deleting by tag name where the API wants the numeric id —
is restored as an explicit Gotcha because it destroys the wrong release
silently.

Elsewhere the `exclusive` flag was documented on the wrong side of the
read/write split, and label data from one instance was presented as though it
were universal, which invites an agent to assume a taxonomy that does not
exist on the target repo. rename_branch was missing from the branch surface.
Reference prose and fences are cleaned up in passing.

plugins/gitea/skills/gitea-labels-milestones/SKILL.md

@@ -24,7 +24,7 @@ allowed-tools: Bash mcp__gitea__label_read mcp__gitea__label_write mcp__gitea__m
 
 - **Applying a label takes a numeric ID, but issue/PR responses slim labels down to name strings.** An issue's existing labels yield no IDs — resolve name → ID with `label_read`.
 - **`pull_request_read` returns `milestone` as a bare title string** where `issue_read` returns `{id, title}` — recover the milestone's ID by listing milestones and matching the title.
-- **Never assume a `Kind/*`/`Priority/*`/`Status/*` scope is exclusive — read each label's own `exclusive` field.** `list_repo_labels` returns it per repo label, it is not org-only, and where it is `true` Gitea enforces one-per-scope itself. Replacing rather than stacking on a label whose `exclusive` is `false` destroys a valid label.
+- **Never assume a `Kind/*`/`Priority/*`/`Status/*` scope is exclusive — read each label's own `exclusive` field.** `list_repo_labels` returns it on every repo label, so it is always *readable* per label; `label_write` documents it as "(org only)" because it is only *settable* through the org create methods. Where it is `true` Gitea enforces one-per-scope itself, and replacing rather than stacking on a label whose `exclusive` is `false` destroys a valid label.
 
 ## Step 1 — Resolve owner, repo and org