docs: trim repeated boilerplate in git, gitea, and bin skills

Finding 13: five blocks of near-identical wording were repeated across
skills within a plugin — the gitea "resolve owner and repo" step (5
skills), the 404-masks-403 note (6 files), the manual pagination
explanation (8 files), the git plugin's main/master force-push refusal
(7 files, some with multiple internal restatements), and the bin
skills' domain-glossary/ADR paragraph (5 skills). Tightened each
instance in place — same meaning, fewer words — rather than extracting
to a shared file, which ADR-0014's one-file-per-skill install
constraint rules out. Left the three git skills' structured-result
JSON shapes alone (coupled to the separate, out-of-scope git-orchestrate
merge candidate, finding 19).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YR2CjVumUbEGWcMikcoXBD

plugins/gitea/skills/gitea-branches/references/branches.md

@@ -29,8 +29,7 @@ list_branches owner: <owner> repo: <repo>
 **Response:** one object per branch: `name`, `protected` (bool), `commit_sha` (present when the
 underlying commit data is available).
 
-Paginate if you need the full list (see Gotchas in SKILL.md) — iterate `page` until the returned
-count is less than `per_page`.
+Paginate for the full list (see Gotchas) — iterate `page` until the count is less than `per_page`.
 
 ## `create_branch`