feat(gitea): add gitea-releases skill

Covers releases and tags (list/get/create/delete) — all verified
working with the current write:issue/write:repository token scope.

plugins/gitea/skills/gitea-releases/references/conventions.md

@@ -0,0 +1,40 @@
+---
+topic: conventions
+source_keys:
+  - context7-websites-gitea
+  - context7-gitea-tea-cli
+---
+
+# Release and tag conventions
+
+Practitioner conventions that inform *how* to use the mechanics in `call-signatures.md` — not
+additional tool schemas.
+
+## Release wraps a tag, not the reverse
+
+A release is a title, body (notes), and draft/prerelease flags layered on top of an existing or
+newly-created tag. The tag is the git-level object (a name pointing at a commit); the release is a
+Gitea-level metadata wrapper around it. This is why `delete_release` and `delete_tag` are separate
+calls with separate identifiers (numeric id vs. tag name) — removing the wrapper never implies
+removing the underlying pointer, and vice versa.
+
+## Semver tag naming
+
+Per the `tea` CLI (the reference Gitea client), tag names conventionally follow semver with a `v`
+prefix: `v1.2.0`, `v2.0.0-beta.1`. This is a convention observed by tooling and humans, not a
+Gitea-enforced constraint — the API accepts any string as `tag_name`. Don't validate or rewrite a
+caller-supplied tag name against semver; just pass it through.
+
+## Draft and prerelease are explicit flags
+
+`draft` and `is_pre_release`/`prerelease` are booleans the caller sets directly on `create_release`
+— Gitea does not infer either from the tag name, even though the `-beta`/`-rc` suffix convention
+above is commonly used to signal a prerelease to humans. When a user asks to "cut a beta" or
+"publish a release candidate," set `is_pre_release: true` explicitly in the same call rather than
+relying on the tag string to carry that meaning.
+
+## Release notes sourcing
+
+Practitioner convention (per `tea`) is to source release notes (`body`) from a changelog file
+rather than typing them inline for each release — useful context when a caller asks to "generate"
+or "use the changelog for" release notes rather than write them from scratch.