[Chore] Forbid citing umbrella tickets as references

.github/copilot-instructions.md

@@ -23,6 +23,8 @@
   and dashes.
 - Commit subject: `[ISSUE-ID] Brief description`. Uppercase first letter,
   imperative mood, target ≤50 chars (hard limit 72), no trailing period.
+  With no dedicated issue, use `[Chore]` — never a project-wide or
+  time-tracking ticket.
 - Commit body: blank line after subject, then `Problem: …` paragraph,
   then `Solution: …` paragraph. Body is mandatory.
 - All commits must be signed.

plugins/serokell-global/skills/bootstrap-repo/SKILL.md

@@ -48,10 +48,13 @@ requires:
      several skills read it.
      - Customer-facing projects use YouTrack as primary issue
        tracker, YT project key should be recorded.
-     - Small utility repositories use single YouTrack umbrella ticket
-       for time tracking, dedicated to project maintenance; GitHub is
-       used as issue tracker, and "team lead" term de-facto indicates
-       the project owner.
+     - Small utility repositories use GitHub as issue tracker, and
+       "team lead" term de-facto indicates the project owner. Time is
+       logged against a single YouTrack umbrella ticket dedicated to
+       project maintenance; record it on a separate `Time tracking:`
+       line, not as the issue tracker. It exists only for time
+       logging — never cite it in branch names, commits, PRs, or
+       changelog entries.
    - License + `LICENSES/` + root `LICENSE` → `license-choice` skill.
    - SPDX headers on every file → `reuse-headers` skill.
    - README rewritten to Standard Readme → `readme` skill.

plugins/serokell-global/skills/changelog/SKILL.md

@@ -30,7 +30,11 @@ Regardless of format:
   "Refactored Z". Prefer too much detail over too little — a reader
   six months from now should be able to act on the entry without
   re-reading the PR.
-- **PR or issue reference** alongside each bullet (e.g. `(#123)`).
+- **PR or issue reference** alongside each bullet (e.g. `(#123)`):
+  the PR itself, or the issue the change resolves. Never cite a
+  project-wide ticket, such as a YouTrack umbrella ticket used for time
+  tracking — it says nothing about the change. With no dedicated issue,
+  the PR number alone is enough.
 - **Breaking changes** clearly marked (e.g. a leading `BREAKING:` tag
   or a separate "Breaking changes" subsection), with **migration
   guidance** — inline if short, or a link to a longer migration doc.

plugins/serokell-global/skills/committing-work/SKILL.md

@@ -67,6 +67,8 @@ Subject line:
 - Prefix with issue IDs in square brackets: `[#453]`, `[GHC-8]`. Omit if
   the repository is public and the issue is in a private tracker (e.g.
   YouTrack).
+- With no dedicated issue (e.g. small maintenance), prefix with
+  `[Chore]`. Don't substitute a project-wide or time-tracking ticket.
 - Start with an uppercase letter.
 - Use the imperative mood ("Switch from X to Y", not "Switched" or "Switches").
 - Target ≤50 characters; hard limit 72.
@@ -133,4 +135,3 @@ git commit --fixup=<sha-of-the-commit-being-fixed>
 
 `git rebase -i --autosquash <target>` then auto-orders and marks
 these `fixup!` commits to be squashed when the history is cleaned up.
-

plugins/serokell-global/skills/pull-requests/SKILL.md

@@ -16,6 +16,8 @@ Scheme: `[ISSUE-ID] Brief description`.
 
 - Omit `[ISSUE-ID]` if the repository is public and the issue is in a
   private tracker (e.g. YouTrack).
+- With no dedicated issue, use `[Chore]`, as for commits (see the
+  `committing-work` skill).
 - Brief description: short but understandable on its own.
 
 ## Description
@@ -33,7 +35,8 @@ Must not be empty.
   `Fixed #N` / `Resolves #N` to auto-close them on merge. For YouTrack
   issues, paste the full URL
   (`https://issues.serokell.io/issue/<PROJECT>-<N>`) prefixed with
-  `Resolves`.
+  `Resolves`. With no dedicated issue, write `None` — don't link a
+  project-wide or time-tracking ticket.
 - Move the linked issue's state forward now, not after merge:
   YouTrack → `Review` (see the `youtrack-issues` skill). GitHub /
   GitLab issues → if the project tracks state via labels, apply the