perf(web): ratchet the change-detection ticks that zoneless made deterministic

On the canonical runner (Performance ratchet run 38359088033, three runs
of this branch, five iterations each) renderer.cdTicksToFirstCard read 5,
renderer.cdTicksIdle30s 3 and renderer.cdTicksToFirstPage 9 in all 15
iterations, against 31, 1 to 4 and 22 with zone.js. They become baselines
with zero slack and the Performance journeys job checks them. J3 and J4
tick counts still vary by one and stay unenforced; J3 wall clock is in
master's range, so the local rise measured on #1824 was machine load.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture/performance-journeys.md

@@ -1424,8 +1424,12 @@ Not enforced, with the reason:
 - Every `renderer.longTasks` (J1 2 or 1, J2 0 with one 1 earlier in the
   week, J3 1 or 2 until #1817 and 0 since): a long task is a task over
   50 ms, so the count follows runner speed, not work.
-- Every `cdTicks` counter: the zoneless migration (plan item C6) changes
-  them.
+- J3 `renderer.cdTicksToPlaying` (7 or 8) and J4
+  `renderer.cdTicksToResults` (10 or 11): not identical even zoneless; the
+  player's and the search debounce's events land in one or two ticks. J1
+  `renderer.cdTicksToFirstCard` (5), `renderer.cdTicksIdle30s` (3) and J2
+  `renderer.cdTicksToFirstPage` (9) are enforced since the zoneless flip
+  (#1929), identical in all 15 iterations of its three dispatched runs.
 - J2 `renderer.domMutationsToFirstPage`: 1,602 or 1,603 between runs of
   recent commits.
 - J3 `renderer.ipcCallsToPlaying` (4 or 5) and

docs/architecture/zoneless-migration.md

@@ -305,6 +305,24 @@ Build `electron-performance` and run the journeys as described in
 [performance journeys](performance-journeys.md), then paste
 `renderer.cdTicksToFirstCard`, `renderer.cdTicksIdle30s`,
 `renderer.cdTicksToFirstPage` and `renderer.cdTicksToPlaying` before and
-after. While zone.js is on, removing Eager does not change the number of
-ticks, only the work per tick; expect the counters to stay put until the flag
-PR and the template work (DOM mutations, profile time) to drop.
+after. Until the flip, while zone.js was on, removing Eager did not change
+the number of ticks, only the work per tick. Since the flip (#1929)
+`renderer.cdTicksToFirstCard` (5), `renderer.cdTicksIdle30s` (3) and
+`renderer.cdTicksToFirstPage` (9) are ratchet baselines: a change that adds a
+tick to launch, to the idle dashboard or to opening a source fails the
+journeys job.
+
+Canonical runner (`Performance ratchet` dispatched on #1929, three runs, five
+iterations each) against `master` the same day with zone.js:
+
+| Counter | `master` (zone.js) | #1929 (zoneless) |
+| --- | --- | --- |
+| `renderer.cdTicksToFirstCard` | 31 (2026-10-04) | 5 |
+| `renderer.cdTicksIdle30s` | 1 to 4 | 3 |
+| `renderer.cdTicksToFirstPage` | 22 | 9 |
+| `renderer.cdTicksToPlaying` | 15 to 17 | 7 or 8 |
+| `renderer.initialBytes` | 1,596,201 | 1,545,931 |
+| J3 `clickToPlayingMs` p50 | 151.6, 159.2, 185.7 | 128.0, 178.6, 189.5 |
+
+J3 wall clock is in the same range, so the local rise measured on the flag
+PR was machine load.