README: generate shortcuts table from shortcuts.ts (single source of truth)

The shortcuts table in README was hand-maintained and kept drifting from
src/lib/shortcuts.ts (the data the in-app help overlay reads). Replace the
table with a marker block (<!-- SHORTCUTS:START --> ... <!-- SHORTCUTS:END -->)
populated by scripts/gen-readme-shortcuts.mjs. Includes TIPS too, not just
shortcuts. Script is plain Node + fs (no tsx/esbuild dep); reads shortcuts.ts
as text, strips TS type syntax, dynamic-imports the resulting .mjs.

Adds `pnpm gen:readme` script and a `--check` mode that exits 1 on drift
(for future CI wiring). Idempotent.

memory.md

@@ -90,6 +90,21 @@ Open follow-ups specific to this session:
 - **Probe latency-as-jitter.** First idle tick after 5s silence triggers a 100-300ms `wsl.exe` shell-out. The user sees the red border flicker on for ~one tick before the probe resolves and clears it. Not visually obvious in practice (the red is already a transient signal), but could pre-warm the cache on a slower interval if it bites.
 - **PowerShell idle filter.** PS has no `ps` equivalent we can probe cheaply; closest is `Get-Process` + a watched-list mapping (`claude` doesn't exist on Windows, but `cargo`, `npm`, `python` do). Defer until someone actually runs a long-running CLI in PS and complains.
 - **Workspace-edit migration of the `LeafPane.svelte` mention** in the open-question section about the 5000ms threshold — file says `.svelte` but we're React now. Drive-by, not done here ("don't refactor unrelated code").
+### 2026-05-26 — README shortcut table now generated from `shortcuts.ts`
+
+The keyboard-shortcut table in README and the in-app help overlay used to be hand-mirrored copies maintained by "keep in sync" comments. They drifted (most recently the navigation/font-size entries diverged). Now `src/lib/shortcuts.ts` is the single source of truth and README's section is generated from it.
+
+**Marker shape:** plain HTML comments — `<!-- SHORTCUTS:START -->` and `<!-- SHORTCUTS:END -->`. Markdown viewers render them as nothing (zero visual noise); the generator finds them by literal string match. They live under the new `### Shortcuts and tips` heading in `Using it`, with explanatory prose + a footer pointer below for readers who reach for the file.
+
+**Script:** `scripts/gen-readme-shortcuts.mjs`. Sibling to `pr4-verify.mjs` / `release.sh` / `make-icon.py`. Plain Node + `fs` only — no tsx/esbuild dep. Trick: shortcuts.ts is pure data (no React, no value imports), so the script reads it as text, strips `export interface { ... }` blocks with a brace-walker, drops the `: SomeType[]` annotations on the `export const` declarations, writes the result to a temp `.mjs` file in `os.tmpdir()`, and dynamic-imports it. Cleaner than a regex parser of the array literal because any future shape change in shortcuts.ts (adding a new field, reshuffling sections) Just Works.
+
+**Render style:** mirrors the existing README table — `| Key | Action |` two-column, keys backticked. The TS data is grouped by section, so each section gets a `**Title**` subheading + its own table. TIPS render as a `**Title** — body` bulleted list. Pipes in cell text are escaped to `\|`; newlines collapse to spaces.
+
+**Pnpm script:** `pnpm gen:readme`. Also supports `--check` mode (`node scripts/gen-readme-shortcuts.mjs --check`) which exits 1 if the README would change — wire it into CI later if drift starts mattering again.
+
+**To add or change a shortcut/tip:** edit `src/lib/shortcuts.ts`, run `pnpm gen:readme`. The help overlay updates automatically (it already imports from there); the README marker block updates from the same source. Don't hand-edit anything between the marker comments — your changes will be wiped on the next regen.
+
+**Verified:** ran twice, second run reports "already up to date" with empty `git diff`. `pnpm check` clean (tsc --noEmit, exit 0).
 
 ### 2026-05-26 — Hard-deny: PowerShell patterns + label list de-duplicated