agent: dogfood polish 2026/04/19 — Linux native chrome + History redesign + mic picker cleanup

Second dogfood sprint. Headline fix: Linux now uses native KWin/Mutter
decorations instead of fragile frameless `startResizeDragging`, which
collapsed diagonal corner resize to a single axis and made drag feel
laggy. macOS / Windows keep custom chrome via `useCustomChrome` gate.

Other changes:

- Cross-window preferences sync via `kon:preferences-changed` Tauri
  event — theme and font changes propagate live to float/viewer.
- Hotkey recorder rewritten to use capture-phase document listener
  gated by $effect; button focus was unreliable in webkit2gtk.
- History page redesigned for cognitive-load hygiene: title-first
  compact row, inline title input, Edit popout opening /viewer in
  edit mode, clipboard export as .md with YAML frontmatter, manual
  tag chips + + Add tag input, header tag filter (cap 7), global
  Starred filter, `tag:xyz` search syntax.
- `deriveAutoTags` kept as empty hook for post-Task-7 LLM topic tags;
  research found all previous auto-tag chips redundant with row UI.
- Viewer window adds edit mode with debounced-save textarea; native
  title renamed to "Kon - Transcription Editor".
- Window minimums updated per GNOME HIG + WCAG reflow research:
  main 960x600, float 360x480, editor 560x520.
- Microphone picker filters raw ALSA strings (hw:, plughw:, front:,
  sysdefault:, null) and dedupes by CARD=X. New `description` field
  on DeviceInfo reads /proc/asound/cards so Blue Yeti shows as "Blue
  Microphones" instead of the short "Microphones" card name.
- GPU reporting fixed: get_runtime_capabilities now returns
  accelerators=[cpu,vulkan] and whisper.supports_gpu=true, matching
  the transcribe-rs whisper-vulkan feature linked unconditionally.
- ResizeHandles kept for macOS/Windows frameless: 12px edges, 20px
  corners via CSS vars, pointerdown + setPointerCapture, corners
  above edges in z-order, rendered as sibling (not child) of the
  animated layout root so `position: fixed` is viewport-relative.
- Dueling drag-region handlers removed — `data-tauri-drag-region` and
  manual `startDragging()` were stacked on the same elements; kept
  the manual handler which has the button/input early-return logic.

See HANDOVER.md for the full session log and deferred items.

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

src/lib/pages/SettingsPage.svelte

@@ -34,6 +34,64 @@
   let audioDevices = $state([]);
   let audioDevicesError = $state(null);
 
+  // ALSA enumeration leaks raw device strings (hw:, plughw:, front:,
+  // sysdefault:, back:, surround:, iec958:, dmix:, usbstream:, plus a
+  // bogus "null" device). These are kernel-level aliases — no user
+  // needs to pick between "hw:CARD=2,DEV=0" and "plughw:CARD=2,DEV=0".
+  //
+  // The strategy: keep a small set of well-known sentinel devices
+  // (default/pipewire/pulse), then pull a single entry per unique
+  // sound card by parsing CARD=X from the sysdefault: alias. That
+  // gives us "Microphones" / "C920" / "Generic" as friendly labels
+  // while mapping them to a reliable ALSA path.
+  const SENTINEL_DEVICES = new Set(["default", "pipewire", "pulse"]);
+
+  function parseCardName(name) {
+    const match = String(name || "").match(/CARD=([^,]+)/);
+    return match ? match[1] : null;
+  }
+
+  function buildVisibleDevices(devices) {
+    const out = [];
+    const seenCards = new Set();
+
+    for (const dev of devices) {
+      const name = dev?.name || "";
+      if (!name || name === "null") continue;
+      if (SENTINEL_DEVICES.has(name)) {
+        out.push(dev);
+        continue;
+      }
+      if (name.startsWith("sysdefault:CARD=")) {
+        const card = parseCardName(name);
+        if (card && !seenCards.has(card)) {
+          seenCards.add(card);
+          out.push(dev);
+        }
+      }
+      // Everything else (hw:, plughw:, front:, dmix:, etc.) is silently
+      // dropped — cpal will resolve the sysdefault:CARD= form fine.
+    }
+    return out;
+  }
+
+  function friendlyLabel(dev) {
+    const name = dev?.name || "";
+    if (name === "default") return "System default";
+    if (name === "pipewire") return "PipeWire";
+    if (name === "pulse") return "PulseAudio";
+    // Prefer the rich product description from /proc/asound/cards
+    // (e.g. "Blue Microphones" for the Yeti). Falls back to the raw
+    // CARD=X short name if we couldn't load descriptions.
+    const desc = (dev?.description || "").trim();
+    if (desc) return desc;
+    const card = parseCardName(name);
+    if (card) return card;
+    return name;
+  }
+
+  let visibleAudioDevices = $derived(buildVisibleDevices(audioDevices));
+
   async function refreshAudioDevices() {
     audioDevicesError = null;
     try {
@@ -448,11 +506,9 @@
                   onfocus={refreshAudioDevices}
                 >
                   <option value="">Auto (recommended) — let Kon pick the working mic</option>
-                  {#each audioDevices as dev}
+                  {#each visibleAudioDevices as dev}
                     <option value={dev.name} disabled={dev.is_likely_monitor}>
-                      {dev.name}
-                      {dev.is_default ? " (system default)" : ""}
-                      {dev.is_likely_monitor ? " — speaker monitor, skip" : ""}
+                      {friendlyLabel(dev)}{#if dev.is_default && dev.name !== "default"} (system default){/if}{#if dev.is_likely_monitor} — speaker monitor, skip{/if}
                     </option>
                   {/each}
                 </select>
@@ -464,7 +520,7 @@
               </div>
               {#if audioDevicesError}
                 <p class="text-[11px] text-error mt-2">{audioDevicesError}</p>
-              {:else if audioDevices.length === 0}
+              {:else if visibleAudioDevices.length === 0}
                 <p class="text-[11px] text-text-tertiary mt-2">No input devices detected. Check that a microphone is connected and PulseAudio/PipeWire is running.</p>
               {:else}
                 <p class="text-[11px] text-text-tertiary mt-2">