Fix Garmin connect race, surface tool error content, add dev start scripts

- GarminConnection now flushes Profile's pending debounced autosave before
  connecting, avoiding a race where Connect fires with stale credentials.
- client.go reads res.Content before checking IsError so tool error
  messages actually include mcp-garmin's response text.
- seedsample: update kind lookups to match current taxonomy names
  ("Easy Run" -> "Easy", "Interval" -> "Intervals").
- Add backend/start.sh and frontend/start.sh dev launch scripts, and
  check in CLAUDE.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/package-lock.json

@@ -212,9 +212,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -232,9 +229,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -252,9 +246,6 @@
         "ppc64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -272,9 +263,6 @@
         "riscv64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -292,9 +280,6 @@
         "riscv64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -312,9 +297,6 @@
         "s390x"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -332,9 +314,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -352,9 +331,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -551,9 +527,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -571,9 +544,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -591,9 +561,6 @@
         "ppc64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -611,9 +578,6 @@
         "s390x"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -631,9 +595,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -651,9 +612,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MIT",
       "optional": true,
       "os": [
@@ -1252,9 +1210,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MPL-2.0",
       "optional": true,
       "os": [
@@ -1276,9 +1231,6 @@
         "arm64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MPL-2.0",
       "optional": true,
       "os": [
@@ -1300,9 +1252,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "glibc"
-      ],
       "license": "MPL-2.0",
       "optional": true,
       "os": [
@@ -1324,9 +1273,6 @@
         "x64"
       ],
       "dev": true,
-      "libc": [
-        "musl"
-      ],
       "license": "MPL-2.0",
       "optional": true,
       "os": [

frontend/src/components/GarminConnection.tsx

@@ -14,7 +14,7 @@ function syncProgressLabel(status: SyncStatus): string {
   return "syncing...";
 }
 
-export function GarminConnection() {
+export function GarminConnection({ onBeforeConnect }: { onBeforeConnect?: () => Promise<void> }) {
   const [auth, setAuth] = useState<AuthResponse | null>(null);
   const [code, setCode] = useState("");
   const [busy, setBusy] = useState(false);
@@ -50,6 +50,7 @@ export function GarminConnection() {
     setBusy(true);
     setError(null);
     try {
+      await onBeforeConnect?.();
       setAuth(await api.login());
       setDisconnected(false);
     } catch (e) {

frontend/src/pages/Profile.tsx

@@ -88,6 +88,18 @@ export function Profile({ onSaved }: { onSaved?: (p: ProfileType) => void }) {
     saveTimeoutRef.current = setTimeout(() => persist(next), AUTO_SAVE_DELAY_MS);
   }
 
+  // GarminConnection's "Connect" button reads credentials from the backend's
+  // in-memory profile, which only updates once the debounced autosave above
+  // actually fires -- clicking Connect right after typing a password would
+  // otherwise race it and authenticate with stale (possibly empty) creds.
+  async function flushPendingSave() {
+    if (saveTimeoutRef.current) {
+      clearTimeout(saveTimeoutRef.current);
+      saveTimeoutRef.current = null;
+      if (profileRef.current) await persist(profileRef.current);
+    }
+  }
+
   if (!profile) {
     return (
       <div className="page">
@@ -132,7 +144,7 @@ export function Profile({ onSaved }: { onSaved?: (p: ProfileType) => void }) {
           value={profile.BackfillHorizonDays}
           onChange={(v) => set("BackfillHorizonDays", v)}
         />
-        <GarminConnection />
+        <GarminConnection onBeforeConnect={flushPendingSave} />
       </fieldset>
 
       {/* TODO: these settings currently have no explanation in the UI --

frontend/start.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+set -euo pipefail
+cd "$(dirname "$0")"
+
+# node/npm are installed via Homebrew (node@22) but not linked onto PATH.
+export PATH="/opt/homebrew/opt/node@22/bin:$PATH"
+
+if [ ! -d node_modules ]; then
+  npm install
+fi
+
+exec npm run dev