Remove QR sharing; README accuracy pass

Drop the QR-code share button, its external-service warning banner/CSS,
and the api.qrserver.com handler — sharing is now copy/open link only, so
the app makes no external requests at all. README: remove QR references
and the Deploy section, refresh Features/sounds/dynamics/swing, list the
808/909 voices, and note which acoustic voices use CC0 samples.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -2,8 +2,8 @@
 
 A browser **polymetric groove trainer / metronome** — and the design mockup for a
 Raspberry Pi Pico hardware build. Stack as many "meter lanes" as you like; each is
-its own little metronome with a grouping, subdivision, drum voice and per-beat
+its own little metronome with a grouping, subdivision, drum voice and a per-step
-pattern. Layering lanes produces polymeter and true ratio polyrhythm.
+pattern with accents. Layering lanes produces polymeter and true ratio polyrhythm.
 
 **Live:** https://metronome.varasys.io
 
@@ -18,17 +18,18 @@ the browser may not persist `localStorage` between sessions, so use **Export all
 
 ## Features
 
-- **Meter lanes** — grouping (odd meters), subdivision, a synthesized drum/percussion voice, per‑beat
+- **Meter lanes** — grouping (odd meters), subdivision (incl. swing), a drum/percussion
-  on/off pattern (rests), mute, live measure counter.
+  voice, per‑**step dynamics** (accent / normal / ghost / mute), mute, live measure counter.
+- **Sounds** — a sampled acoustic kit plus synthesized **808 / 909** and electronic voices;
+  click each pad to set its dynamics; pick a *swing* subdivision for a triplet feel.
 - **Polyrhythm** — a per‑lane *poly* toggle fits a lane's beats evenly into lane 1's
   bar (e.g. 5‑over‑4, 3‑over‑2).
 - **Practice** — gap/mute trainer (play N / mute M bars) and a tempo ramp with a
   start BPM and signed step.
-- **Set lists** — named, ordered lists of saved setups; click an item to load it
+- **Set lists** — named, ordered lists of saved setups; **cue** across lists and commit
-  (it switches live if you're already playing), **N** loads the next; each play is
+  on a bar/beat boundary with no audible gap (see **Live performance**); each play is
   logged for cross‑day comparison.
-- **Sharing** — copy a link to your current settings or a whole set list (with an
+- **Sharing** — copy a link to your current settings or a whole set list.
-  optional QR generated by an external service).
 - **Theming** — System / Light / Dark.
 
 ## The share language
@@ -39,7 +40,7 @@ goes in a share link, and you can hand‑write or edit it.
 ### Patch grammar
 
 ```
-v1 ; t<bpm> [; vol<pct>] ; <lane> ; <lane> … [; tr<play>/<mute>] [; rmp<start>/<step>/<every>]
+v1 ; t<bpm> [; vol<pct>] [; cd<sec>] [; b<bars>] ; <lane> … [; tr<play>/<mute>] [; rmp<start>/<step>/<every>]
 ```
 
 | Token | Meaning | Example |
@@ -47,6 +48,8 @@ v1 ; t<bpm> [; vol<pct>] ; <lane> ; <lane> … [; tr<play>/<mute>] [; rmp<start>
 | `v1` | format version (always first) | `v1` |
 | `t<bpm>` | tempo | `t120` |
 | `vol<pct>` | master volume 0–100 | `vol70` |
+| `cd<sec>` | time countdown, seconds (auto-advance with Continue) | `cd60` |
+| `b<bars>` | segment length in bars (auto-advance with Continue) | `b16` |
 | `tr<play>/<mute>` | gap trainer: play N bars, mute M | `tr2/2` |
 | `rmp<start>/<step>/<every>` | tempo ramp: start BPM, ±step, every N bars | `rmp80/5/4` |
 | `<lane>` | a meter lane (see below) | `kick:4` |
@@ -59,20 +62,24 @@ Tokens are joined with `;`. `tr` and `rmp` are omitted when off.
 <sound> : <grouping> [ / <sub> ] [ = <pattern> ] [ ~ ] [ ! ]
 ```
 
-- **sound** — one of:
+- **sound** — the acoustic kit: `beep`, `kick`, `snare`, `rim`, `clap`, `hatClosed`,
-  `beep`, `kick`, `snare`, `rim`, `clap`, `hatClosed`, `hatOpen`, `ride`, `crash`,
+  `hatOpen`, `ride`, `crash`, `tomLow`, `tomMid`, `tomHigh`, `tambourine`, `cowbell`,
-  `tomLow`, `tomMid`, `tomHigh`, `tambourine`, `cowbell`, `woodblock`, `claves`,
+  `woodblock`, `claves`, `jamblock` (kick / snare / closed‑hat / crash play embedded
-  `jamblock` (unknown → `beep`).
+  CC0 samples, the rest are synthesized); plus synthesized drum machines —
+  `kick808 snare808 clap808 hat808 openHat808 cowbell808 tom808` and
+  `kick909 snare909 clap909 hat909 ride909 crash909`. Unknown → `beep`.
 - **grouping** — beats per bar, optionally grouped for odd meters: `4`, `3`,
-  `2+2+3`. The first beat of each group is accented.
+  `2+2+3`. Groups get a visual divider; accents are per‑step (see `=pattern`).
 - **`/sub`** — subdivision: `1` quarter (default), `2` eighth, `3` triplet,
   `4` sixteenth, `6` sextuplet. This also sets how many **pads** each beat splits
-  into (a beat becomes `sub` individually‑toggleable steps). Omit for quarter.
+  into. Append **`s`** for **swing** on even subdivisions — `2s` (swung eighths) or
-- **`=pattern`** — per‑**step** on/off as `x`/`.`, length = beats per bar × `sub`
+  `4s` (swung sixteenths) delay the off‑beats to a triplet (2:1) feel. Omit for quarter.
-  (one char per pad). Omit = all on. e.g. `4=.x.x` is a backbeat on 2 & 4;
+- **`=pattern`** — per‑**step dynamics**, one char per pad: **`X`** accent, **`x`**
-  `4/4=x..x..x.x...x...` is a sixteenth‑grid pattern. A short pattern whose length
+  normal, **`g`** ghost (soft), **`.`** mute (rest). Length = beats per bar × `sub`. Omit to get the
-  equals just the beat count is still accepted and expanded across each beat's
+  default — the first step of **each beat** accented, the rest normal (click a pad in
-  subdivisions (back‑compat).
+  the UI to cycle accent → normal → ghost → mute). e.g. `4=.X.X` accents the backbeat (2 & 4);
+  `4/2s` is swung eighths with the default accents. (Legacy `x`/`.` on/off patterns and
+  short beat‑count patterns still parse.)
 - **`~`** — polyrhythm: fit this lane's beats evenly into **lane 1's** bar.
 - **`!`** — mute the lane.
 
@@ -81,8 +88,9 @@ Tokens are joined with `;`. `tr` and `rmp` are omitted when off.
 | Patch / lane | What it is |
 |---|---|
 | `kick:4` | kick on 4 quarter beats |
-| `snare:4=.x.x` | snare backbeat (2 & 4) |
+| `snare:4=.X.X` | accented snare backbeat (2 & 4) |
-| `hatClosed:4/2` | eighth‑note hi‑hats |
+| `hatClosed:4/2` | eighth‑note hi‑hats (downbeat of each beat accented) |
+| `ride:4/2s` | **swung** eighth‑note ride |
 | `claves:5~` | 5 evenly across lane 1's bar (5‑over‑4 if lane 1 is `4`) |
 | `kick:2+2+3=x..x..x` | 7/8, kick on each group start |
 | `cowbell:3+2/2` | 5/4 grouped 3+2, eighth subdivision |
@@ -102,10 +110,7 @@ clears the hash so a refresh won't re‑import.
 
 In the set‑list panel's **⋯** menu:
 - **Share settings link** / **Share set‑list link** open a dialog with the link to
-  **Copy** or **Open**.
+  **Copy** or **Open**. The link encodes everything in the URL — nothing is uploaded.
-- **QR ↗** opens a third‑party QR service (api.qrserver.com) with the link in its
-  URL so you can scan it on a phone. A banner warns you it's external — confirm the
-  QR decodes to the shown link before trusting it. (No QR is generated locally.)
 - **Export all / Import file** back up your set lists and practice log as a JSON
   file (a legacy `presets` field is included for backward compatibility).
 
@@ -115,15 +120,36 @@ In the set‑list panel's **⋯** menu:
 |-----|--------|
 | `Space` | play / stop (works everywhere except while typing in a text field) |
 | `T` | tap tempo |
-| `↑` / `↓` | tempo ±1 (`Shift` = ±10) |
+| `←` / `→` | tempo ±1 (`Shift` = ±10) |
 | `A` | add meter lane |
-| `N` | load next set‑list item |
+| `↑` / `↓` / `Home` / `End` | move the **cue** cursor (crosses set lists) |
-| `Alt`+`↑` / `Alt`+`↓` | reorder the selected set‑list item |
+| `PgUp` / `PgDn` | cue the previous / next set list |
+| `Enter` | commit the cued item — switches on the next **bar** (smooth) |
+| `Shift`+`Enter` | commit now — switches on the next **beat** (rude) |
+| `N` / `P` | load next / previous immediately (rude quick‑step) |
+| `Alt`+`↑` / `Alt`+`↓` | reorder the cued item |
 | `1`–`9` | enable / silence lane 1–9 |
 | `?` | shortcuts help |
-| `Esc` | close the help / share dialog |
+| `Esc` | close the help / share dialog · cancel an armed switch |
 
-(Arrow keys are left alone while a slider or dropdown is focused, so they still adjust it.)
+(Arrow / navigation keys are left alone while a slider or dropdown is focused, so they still adjust it.)
+
+## Live performance
+
+The set list is performance-ready: you can line up where you're going next without
+disturbing what's playing, then commit on a musical boundary — no audible gap.
+
+- **Cue, then commit.** The arrows / `Home` / `End` / `PgUp` / `PgDn` move a *cue
+  cursor* (amber outline) through items — across set lists, without loading anything.
+  **`Enter`** commits the cued item with a **smooth** cutover at the next **bar**;
+  **`Shift`+`Enter`** is a **rude** cutover at the next **beat** ("wrong thing playing,
+  fix it now"). `N` / `P` are immediate rude quick‑steps. `Esc` cancels an armed switch.
+- **Bar‑length segments.** Give an item a **bar** count (Timers box, or the `b<n>`
+  patch token) and a bar countdown (▦) shows bars remaining. With **Continue** on, it
+  auto‑advances to the next item at the bar boundary — so a *song* is just a set list
+  of segments (each with its own tempo, ramp and bar length) that hand off seamlessly.
+- All transitions — manual or auto, beat or bar — keep the clock continuous; the loaded
+  item can even live in a set list you're not currently viewing (the player names it).
 
 ## Versioning
 
@@ -136,12 +162,6 @@ Cut a release with `./release.sh [X.Y.Z]` — the optional arg bumps & commits
 `VERSION`; it then tags the current commit `v<VERSION>` (requires a clean tree).
 Push the tag, then deploy.
 
-## Deploy
-
-`./deploy.sh` copies `index.html` (version‑stamped) into the Caddy
-web root and smoke‑tests the live URL. No restart needed (`file_server` picks up
-changes immediately).
-
 ## Files
 
 | File | Purpose |
@@ -164,3 +184,10 @@ later version. See [`LICENSE`](LICENSE) for the full text.
 Because the app is served over a network, the AGPL's §13 applies: anyone
 interacting with a hosted instance must be able to get its source. The repo
 link in the in‑app **?** help satisfies this.
+
+### Credits
+
+Acoustic drum one‑shots are from the **[Versilian Community Sample Library
+(VCSL)](https://github.com/sgossner/VCSL)**, released under **CC0** (public
+domain) — trimmed and downsampled, embedded inline. The 808/909 voices and the
+electronic/percussion sounds are synthesized in Web Audio (no samples).