fix(notify): scope run/jobs lookups to github.repository with optional run-token

[gamechanger1s]

Bug

The Slack card is missing DURATION and FAILED AT when the caller sets target-repo for cross-org attribution.

notify@v4.0.0 calls the Actions API on target-repo to fill those two rows — but Actions runs only exist in github.repository. So the calls 404, get swallowed by 2>/dev/null, and both rows silently disappear.

Same-repo callers (target-repo == github.repository) never saw it.

Fix

• Look up run/jobs on github.repository (that's where the run actually is — hard-coded, not overridable).
• Add optional run-token for those two calls; falls back to github-token, so existing callers are byte-identical.
• Also fixes a load-time crash from ${{ }} inside the composite action's description: block.

Fully additive — no consumer has to change to keep working.

[gamechanger1s]

Superseded by #23 — same branch (renamed feat/notify-run-token → fix/notify-run-token, fix: is the correct commit type). GitHub auto-closed this PR during the branch rename and does not allow reopen once the head ref is orphaned.