docs(ci): state the measured push-CI model in ci.yml's when-comment (#1326)

Co-authored-by: ops-ci-01 <[email protected]>

.woodpecker/ci.yml

@@ -21,11 +21,19 @@ variables:
   - &enable_pnpm 'corepack enable'
 
 when:
-  # PR + manual CI run on any branch — the pull_request pipeline is the merge gate.
-  # push CI is restricted to protected branches (main) so a feature-branch push no
-  # longer fires a redundant SECOND pipeline alongside its PR pipeline. This ~halves
-  # CI load on the storage-constrained runner with zero loss of gating (branch
-  # protection requires no push/ci status context; main still gets full push CI).
+  # PR + manual CI run on any branch: the pull_request pipeline is the merge
+  # gate (next is protected and the default branch since 2026-08-19).
+  # Push CI runs on main only. next deliberately runs NO push ci: post-merge
+  # verification on next is carried by publish.yml's `verify` step
+  # (pnpm verify:release), which mirrors this pipeline's complete mandatory
+  # set step-for-step, enforced by scripts/verify-release.test.mjs. PR CI
+  # tests the PR HEAD tree (refs/pull/N/head, measured 2026-08-19), not a
+  # merge ref, so if next advances before a merge the landed tree differs
+  # from the tested one; publish verify re-runs the full set on the landed
+  # tree (PGlite path). Measured 2026-08-19: the 21 most recent push events
+  # on next each ran exactly one pipeline (publish), zero ci.
+  # Keeping push ci off next also avoids a redundant second full-suite run
+  # per merge on the storage-constrained runner.
   - event: [pull_request, manual]
   - event: push
     branch: main