research: Strudel.cc live-coding REPL deep dive; SHARD-WP-0004 T5

Code as live time-based audio performance; the far live end of the
live<->snapshot axis (no faithful static form; static = source + marked
recording). The honesty test for graceful degradation. Enrichment-only
(UC-54/55). Marks T5 done — all 8 batch tasks complete.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SCOPE.md

@@ -22,7 +22,7 @@ Learnings update both SCOPE and INTENT where necessary.
 | Research | yawex prior art; c2 origins; federation concepts; wikiengines overview (`research/260608-*/`); XWiki/TWiki/Foswiki deep dives (`research/260613-*/`); Xanadu + ZigZag + Roam + Obsidian + Notion + Joplin + Logseq + local-first workspaces (Anytype/AFFiNE/AppFlowy) + Trilium + Wiki.js + Federated Wiki + Wikibase + git-forge wikis + TiddlyWiki + ikiwiki + Quip + MojoMojo + Oddmuse + UseModWiki deep dives & shard-spectrum synthesis (`research/260614-*/`) |
 | Demand | NetKingdom integration asks captured, not yet negotiated |
 | Spec | Architecture blueprint drafted; UseCaseCatalog 84 UCs from research; PRD/TSD scaffolds |
-| Work | `SHARD-WP-0001` active (6 tasks); `SHARD-WP-0002` active (16 tasks: T1–T10 federation + T11–T16 adapter contract); `SHARD-WP-0003` **done** (9 engine dives complete); `SHARD-WP-0004` active (8 computational-knowledge dives: T1 literate programming, T2 Mathematica, T3 Jupyter, T4 Processing, T6 Squeak + T8 Pharo (merged), T7 Glamorous Toolkit done) |
+| Work | `SHARD-WP-0001` active (6 tasks); `SHARD-WP-0002` active (16 tasks: T1–T10 federation + T11–T16 adapter contract); `SHARD-WP-0003` **done** (9 engine dives complete); `SHARD-WP-0004` active (8 computational-knowledge dives: T1 literate programming, T2 Mathematica, T3 Jupyter, T4 Processing, T5 Strudel, T6 Squeak + T8 Pharo (merged), T7 Glamorous Toolkit done — all 8 dives complete) |
 
 ## In Scope (today)
 

research/260614-strudel-deep-dive/README.md

@@ -0,0 +1,30 @@
+# 260614 — Strudel.cc (live-coding REPL) deep dive
+
+Date: 2026-06-14 · Source: **SHARD-WP-0004 T5**
+
+## What this is
+
+A deep dive into **Strudel.cc** (the JavaScript port of **TidalCycles**): a browser
+**live-coding REPL** where terse **pattern source** is **evaluated live into time-based
+audio** — code as a running musical performance, with **no document, no output cell, no file
+of results**.
+
+## Why it matters
+
+- The **extreme of the live↔snapshot axis** (named at T6): output is **temporal, generative,
+  performative**, so there is **no faithful static form** — the best static projection is
+  **source (canonical, diffable) + an optional audio recording snapshot**, marked as one
+  performance. The **honesty test** for union-without-erasure + graceful degradation.
+- Bounds the projection model's live end: ahead-of-time → view-time one-shot → continuous →
+  **irreducibly live/temporal (recording-only)**.
+
+## Yield
+
+- **No new UC** (enrichment / design prior art; far live end). Enriches **UC-54, UC-55**;
+  links UC-83/84, UC-37, UC-35.
+
+## Contents
+
+| Path | Role |
+|------|------|
+| `findings.md` | Code-as-live-performance, the limit of static projection, INTENT mapping, UC disposition (enrichment-only), architecture notes (T16 far end of live↔snapshot axis) |

research/260614-strudel-deep-dive/findings.md

@@ -0,0 +1,118 @@
+# Strudel.cc — live-coding REPL — deep dive (findings)
+
+**Date:** 2026-06-14 · **Source:** SHARD-WP-0004 T5 · **Subject:** Strudel.cc (the
+JavaScript port of TidalCycles) — a browser **live-coding REPL** where code is a **running
+musical performance**.
+
+## Why this dive
+
+The closing, lowest-priority dive — and the **extreme** of the live↔snapshot axis. Where
+Processing (T4) renders *visual* output at view time, Strudel renders **time-based audio**
+that only exists *while running and evolving*. It is the limit case for "can a page be a live
+computation?" — the answer where **static projection is least faithful**. Enrichment-only;
+feeds UC-54/55 and hardens the snapshot-degradation rule.
+
+## 1. Code as a live, evaluated performance
+
+- **Strudel** ports **TidalCycles**' pattern language to JavaScript, running entirely in the
+  **browser** (Web Audio). You write **pattern expressions** (e.g. `note("c e g")`,
+  `sound("bd sd")` with transformations) and **evaluate them live**; the sound updates
+  **without stopping** — the essence of *live coding*.
+- The artifact is **terse source text** (a pattern); the "content" is the **sound it
+  produces over time**. There is **no document, no output cell, no file of results** —
+  output is **ephemeral, temporal, and performative**.
+- A Strudel "page" (a shared REPL link / snippet) is **source + the implicit promise of a
+  running evaluation**. The source is tiny and diffable; the experience is not capturable as
+  text.
+
+## 2. The limit of static projection
+
+Strudel pushes past Processing on every "live" dimension:
+
+- **Temporal & generative** — output unfolds over time and may be **non-deterministic**
+  (randomness, evolving state). There is no single "frame"; the faithful capture is a
+  **recording (audio), itself just one performance**, not the artifact.
+- **Performative** — the value is partly the **act of live editing**; even a recording loses
+  the live-coding dimension.
+- So on the **live↔snapshot axis** (named at T6), Strudel sits at the **far live end**: the
+  best static projection is **(a) the source** (canonical, diffable) **+ (b) an optional
+  audio recording snapshot**, explicitly marked as one rendering of a live/temporal artifact.
+
+This makes Strudel the **honesty test** for the contract: shard-wiki must be able to attach
+such a source, present it truthfully (here is the source; a live render needs the runtime; a
+recording is one performance), and **never imply a static page captures it**.
+
+## 3. INTENT mapping (enrichment-only — no new UC)
+
+### Reinforcements / refinements
+
+- **Live-evaluated, time-based content (UC-54/55).** Strudel is the extreme executable-as-
+  page: **source canonical, presentation = a temporal live evaluation**. Confirms the page
+  model must represent content whose rendered form is **time-based / generative / performative**.
+- **live↔snapshot axis (T6) — far end.** Establishes the **upper bound**: some content is
+  **irreducibly live**; static projection degrades to **source + a recording snapshot**, with
+  honesty about what's lost. Generalizes Processing's "snapshot frame" to "recording of one
+  performance."
+- **Graceful degradation (INTENT).** A backend that can't run the REPL still serves the
+  **source** (tiny, diffable) and any **recording** as read/projection/backup — the
+  limited-backend-still-usable rule, at the hardest content type.
+- **Union without erasure.** Presenting a Strudel shard must surface "this is a **live
+  temporal artifact**; what you see/hear statically is **source / one recording**" — never
+  hide the liveness or imply completeness.
+
+### Boundaries
+
+- shard-wiki is **not an audio/REPL runtime**; default = attach the **source** + offer/store
+  a **recording** with provenance; live in-viewer evaluation is a gated capability (trust/
+  sandbox, like Processing T4). Source is canonical; everything rendered is a degrading,
+  view-time/temporal projection.
+
+## 4. UC disposition (enrichment-only)
+
+| Mechanism (findings §) | Catalog UC / thread |
+|------------------------|---------------------|
+| Pattern source = live, evaluated, time-based performance (§1) | UC-54 / UC-55 (enriched: time-based/generative executable content) |
+| Output ephemeral/temporal/non-deterministic → no faithful static form (§2) | links live↔snapshot axis (T6), far end |
+| Best static projection = source + audio recording snapshot, marked as one performance (§2) | links UC-83/UC-84 (degrading projection), UC-37 (recording as backup) |
+| Limited backend still serves source + recording (§3) | links UC-37 graceful degradation |
+| Live in-viewer evaluation = capability + trust/sandbox (§3) | links UC-35 |
+
+**No new UC** — Strudel is design prior art marking the **far live end** of the projection/
+liveness model; it adds no orchestration scenario, it bounds one.
+
+## 5. Architecture notes for SHARD-WP-0002
+
+- **T16 (projection):** anchor the **far end of the live↔snapshot axis** — content can be
+  **irreducibly live/temporal/generative**; the contract must allow a projection to declare
+  "no faithful static form; static = source + a marked recording." Combined with T4's
+  **materialization-timing** and **continuity** facets, the projection model now spans:
+  ahead-of-time materialized → view-time one-shot → view-time continuous/interactive →
+  **temporal/generative/performative (recording-only snapshot)**.
+- **T12/T15 (page model):** **time-based / generative executable content** as a page-model
+  edge; source canonical, render temporal.
+- **T11 (capabilities):** "live-evaluate (audio/REPL) in viewer" capability + trust/sandbox;
+  default off → source + recording.
+
+## 6. Open questions
+
+1. Does the contract carry an explicit **"irreducibly live / no faithful static form"** flag
+   on a projection (so the union renders the honest fallback automatically)? (The far-end
+   resolution of the live↔snapshot axis open question from T6.)
+2. Is a **recording** modeled as a stored **derivation-projection snapshot with provenance**
+   (one performance, time T, source rev R), reusing the UC-84 snapshot machinery?
+
+## 7. Sources
+
+- `strudel.cc` (docs, REPL); **TidalCycles** (`tidalcycles.org`) — the pattern language
+  Strudel ports; Web Audio.
+- prior: `research/260614-processing-deep-dive/` (view-time render, continuity, UC-54/55);
+  `research/260614-squeak-pharo-deep-dive/` (live↔snapshot axis);
+  `research/260614-mathematica-deep-dive/` (`Dynamic` interactive, snapshot-only).
+
+## 8. Traceability
+
+**No new UC** (enrichment / design prior art; the far live end). Enriched: UC-54, UC-55;
+links UC-83/UC-84 (degrading projection), UC-37 (recording = backup / graceful degradation),
+UC-35 (live-evaluate capability + trust). Architecture cross-refs: SHARD-WP-0002 T16 (far end
+of live↔snapshot axis: irreducibly-live content, static = source + marked recording), T12/T15
+(time-based/generative executable content), T11 (live-evaluate capability + sandbox).

research/README.md

@@ -43,3 +43,4 @@ when multiple files or sources are involved. Findings here inform `spec/` and
 | 2026-06-14 | `260614-mathematica-deep-dive/` | Mathematica Notebooks — the original computational notebook (`.nb` = a Wolfram expression); nestable cell groups, structured re-evaluable outputs, `Manipulate` live widgets, CDF; confirms UC-84 notebook shape is a genus; SHARD-WP-0004 T2; enrichment-only (reinforces UC-84; UC-54/55) |
 | 2026-06-14 | `260614-squeak-pharo-deep-dive/` | Squeak & Pharo (image-based Smalltalk) — the live-object image (purest "live" end); image-is-not-a-store boundary (export→files only); Pharo Tonel/Iceberg externalizes code to git text; names the live↔snapshot projection axis; SHARD-WP-0004 **T6 + T8** (merged); boundary/enrichment-only, no new UC |
 | 2026-06-14 | `260614-processing-deep-dive/` | Processing / p5.js — program-as-page rendered live at view time (no cached output); adds materialization-timing + continuity facets to projection; execute-in-viewer = capability+trust; SHARD-WP-0004 T4; enrichment-only (UC-54/55) |
+| 2026-06-14 | `260614-strudel-deep-dive/` | Strudel.cc (TidalCycles JS) live-coding REPL — code as live time-based audio performance; the far live end (no faithful static form; static = source + marked recording); honesty test for graceful degradation; SHARD-WP-0004 T5; enrichment-only (UC-54/55) |

spec/UseCaseCatalog.md

@@ -2510,6 +2510,33 @@ captured snapshot/recording; live in-viewer rendering is gated. **No new UC.** A
 logged for `SHARD-WP-0002` (T12/T15/T16/T11): program-as-page (source-canonical/render-
 derived), materialization-timing + continuity facets, view-time-execute capability + sandbox.
 
+### strudel mapping
+
+(Enrichment dive — **no new UC**; design prior art, the far live end. Source: the **Strudel
+deep dive**, `research/260614-strudel-deep-dive/findings.md`.)
+
+| Strudel mechanism (findings §) | Catalog UC / thread |
+|--------------------------------|---------------------|
+| Pattern source = live, evaluated, time-based performance (§1) | UC-54 / UC-55 (enriched: time-based/generative content) |
+| Output ephemeral/temporal/non-deterministic → no faithful static form (§2) | links live↔snapshot axis (T6), far end |
+| Best static projection = source + audio recording snapshot (marked one performance) (§2) | links UC-83/UC-84, UC-37 (recording = backup) |
+| Limited backend still serves source + recording (§3) | links UC-37 (graceful degradation) |
+| Live in-viewer evaluation = capability + trust/sandbox (§3) | links UC-35 |
+
+Note: Strudel (the JS port of TidalCycles) is the **extreme of the live↔snapshot axis** —
+terse **pattern source** evaluated **live into time-based audio**, with output that is
+**temporal, generative, and performative** and therefore has **no faithful static form**. It
+is the **honesty test** for the contract: attach the **source** (tiny, diffable, canonical),
+offer/store an **audio recording** as a marked snapshot (one performance, time T, source rev
+R — reusing UC-84 snapshot machinery), and **never imply a static page captures it**
+(union-without-erasure). It bounds the projection model's **far live end**, completing the
+span ahead-of-time → view-time one-shot → continuous/interactive (Processing) →
+**irreducibly live/temporal (recording-only)**. A limited backend still serves source +
+recording (graceful degradation, UC-37); live in-viewer evaluation is a gated capability
+(trust/sandbox, UC-35). **No new UC.** Architecture logged for `SHARD-WP-0002` (T16/T12/T15/
+T11): far end of the live↔snapshot axis (irreducibly-live content; static = source + marked
+recording), time-based/generative executable content, live-evaluate capability + sandbox.
+
 ---
 
 ## Open questions

workplans/SHARD-WP-0004-computational-knowledge-systems.md

@@ -124,7 +124,7 @@ for the page model (UC-54/55).
 
 ```task
 id: SHARD-WP-0004-T5
-status: todo
+status: done
 priority: low
 state_hub_task_id: "2b099639-3f8b-4b29-a24a-75f7418dd083"
 ```