From e8142730d54a7e6dc8e8a1d24443a93529a77c49 Mon Sep 17 00:00:00 2001
From: Ronald Tse <ronald.tse@ribose.com>
Date: Tue, 1 Sep 2026 08:17:35 +0200
Subject: [PATCH] feat: Range-resumable model downloads (TODO.client-work 09)

Dropped connections resume from the received byte offset (up to 5
attempts); servers that ignore Range restart cleanly instead of
corrupting the artifact.
---
 TODO.client-work/08-neural-demo-island.md     |  5 ++
 TODO.client-work/09-resumable-downloads.md    |  5 ++
 TODO.client-work/10-api-batch-infer.md        |  5 ++
 .../11-confidence-highlighting.md             |  5 ++
 TODO.client-work/12-e3-browser-bench.md       |  5 ++
 src/ml/imf/registry.ts                        | 47 ++++++++++++++-----
 6 files changed, 61 insertions(+), 11 deletions(-)
 create mode 100644 TODO.client-work/08-neural-demo-island.md
 create mode 100644 TODO.client-work/09-resumable-downloads.md
 create mode 100644 TODO.client-work/10-api-batch-infer.md
 create mode 100644 TODO.client-work/11-confidence-highlighting.md
 create mode 100644 TODO.client-work/12-e3-browser-bench.md

diff --git a/TODO.client-work/08-neural-demo-island.md b/TODO.client-work/08-neural-demo-island.md
new file mode 100644
index 0000000..10cbbf8
--- /dev/null
+++ b/TODO.client-work/08-neural-demo-island.md
@@ -0,0 +1,5 @@
+# 08-neural-demo-island
+
+Live neural inference demo on interscript.org: model picker with tier badges + sizes, progress bar during resolve, streaming output, low-confidence highlighting (11), cache/offline status
+
+Status: implementing (2026-09-01).
diff --git a/TODO.client-work/09-resumable-downloads.md b/TODO.client-work/09-resumable-downloads.md
new file mode 100644
index 0000000..db8c75b
--- /dev/null
+++ b/TODO.client-work/09-resumable-downloads.md
@@ -0,0 +1,5 @@
+# 09-resumable-downloads
+
+Range-based resume for flaky networks: interrupted zip downloads continue from the received byte offset instead of restarting 250MB
+
+Status: DONE (2026-09-01) (2026-09-01).
diff --git a/TODO.client-work/10-api-batch-infer.md b/TODO.client-work/10-api-batch-infer.md
new file mode 100644
index 0000000..bf7fd1b
--- /dev/null
+++ b/TODO.client-work/10-api-batch-infer.md
@@ -0,0 +1,5 @@
+# 10-api-batch-infer
+
+POST /v1/infer/batch on the API worker: N inputs per request, sequential Modal upstream, per-item error isolation
+
+Status: implementing (2026-09-01).
diff --git a/TODO.client-work/11-confidence-highlighting.md b/TODO.client-work/11-confidence-highlighting.md
new file mode 100644
index 0000000..f06e647
--- /dev/null
+++ b/TODO.client-work/11-confidence-highlighting.md
@@ -0,0 +1,5 @@
+# 11-confidence-highlighting
+
+Demo UI surfaces onConfidence gaps as output highlighting (low-confidence spans marked)
+
+Status: implementing (2026-09-01).
diff --git a/TODO.client-work/12-e3-browser-bench.md b/TODO.client-work/12-e3-browser-bench.md
new file mode 100644
index 0000000..efb99da
--- /dev/null
+++ b/TODO.client-work/12-e3-browser-bench.md
@@ -0,0 +1,5 @@
+# 12-e3-browser-bench
+
+The browser benchmark cell (paper C): Playwright timing of the real demo page — load, cold/warm cache, decode latency on WASM
+
+Status: implementing (2026-09-01).
diff --git a/src/ml/imf/registry.ts b/src/ml/imf/registry.ts
index 9b893f3..33c86c3 100644
--- a/src/ml/imf/registry.ts
+++ b/src/ml/imf/registry.ts
@@ -185,24 +185,49 @@ async function evictStaleEntries(
   }
 }
 
-/** Fetch with progress via a streamed body (TODO.client-work 03). */
+/** Fetch with progress via a streamed body, resuming across dropped
+ * connections with Range requests (TODO.client-work 03/09): a flaky
+ * network continues from the received byte offset instead of
+ * restarting a 250MB artifact. */
 async function fetchWithProgress(
   url: string,
   onProgress?: (fraction: number, bytes: number) => void,
 ): Promise<Uint8Array> {
   if (!onProgress) return new Uint8Array(await (await fetch(url)).arrayBuffer())
-  const res = await fetch(url)
-  if (!res.ok || !res.body) throw new RegistryError(`fetch failed: ${url} -> ${res.status}`)
-  const total = Number(res.headers.get("content-length") ?? 0)
-  const reader = res.body.getReader()
   const chunks: Uint8Array[] = []
   let received = 0
-  for (;;) {
-    const { done, value } = await reader.read()
-    if (done) break
-    chunks.push(value)
-    received += value.length
-    onProgress(total > 0 ? received / total : 0, received)
+  let total = 0
+  for (let attempt = 0; attempt < 5; attempt++) {
+    let res: Response
+    try {
+      res = await fetch(url, received > 0 ? { headers: { range: `bytes=${received}-` } } : {})
+    } catch {
+      continue
+    }
+    if (!res.ok && res.status !== 206) throw new RegistryError(`fetch failed: ${url} -> ${res.status}`)
+    if (received === 0) total = Number(res.headers.get("content-length") ?? 0)
+    else if (res.status !== 206) {
+      // server ignored Range: restart cleanly rather than corrupt
+      chunks.length = 0
+      received = 0
+      total = Number(res.headers.get("content-length") ?? 0)
+    }
+    const reader = res.body?.getReader()
+    if (!reader) continue
+    let dropped = false
+    for (;;) {
+      try {
+        const { done, value } = await reader.read()
+        if (done) break
+        chunks.push(value)
+        received += value.length
+        onProgress(total > 0 ? Math.min(1, received / total) : 0, received)
+      } catch {
+        dropped = true
+        break
+      }
+    }
+    if (!dropped) break
   }
   const out = new Uint8Array(received)
   let offset = 0