Transfer dialog: relabel conflict radios for single-conflict case

- "Ask for each" was confusing with only one conflict (asking "for each" of 1 makes no sense). Now reads "Ask later".
- Same applies to the other radios: drop "all" when there's only one conflict. "Skip all" → "Skip", "Overwrite all" → "Overwrite", "Overwrite all smaller/older" → "Overwrite if smaller/older".
- Trigger is `totalConflictCount === 1`, not selection size: a single folder containing many conflicts still gets the "all" wording, and 5 selected files with only 1 conflict get the singular wording.
- Backend `ConflictResolution` variants unchanged; this is pure label text.
- Reported by a user test on the conflict dialog.

Author: vdavid

apps/desktop/src/lib/file-operations/CLAUDE.md

@@ -21,7 +21,9 @@ F8/Shift+F8 (trash/delete). Transfer and delete operations share `TransferProgre
    - Optional dry-run scan to detect conflicts upfront
    - Shows sampled conflicts (max 200) with streaming progress
    - User makes conflict decisions before operation starts via a wrap-friendly flexbox of radios: "Skip all", "Overwrite
-     all", "Overwrite all smaller", "Overwrite all older", "Ask for each". The two conditional policies map to the typed
+     all", "Overwrite all smaller", "Overwrite all older", "Ask for each". When `totalConflictCount === 1`, the radio
+     labels drop "all" ("Skip", "Overwrite", "Overwrite if smaller", "Overwrite if older") and "Ask for each" becomes
+     "Ask later" since a single conflict can't be asked "for each". The two conditional policies map to the typed
      `ConflictResolution` variants `overwrite_smaller` / `overwrite_older`; see
      [`src-tauri/.../write_operations/CLAUDE.md`](../../../src-tauri/src/file_system/write_operations/CLAUDE.md) for the
      strict-comparison / fail-closed contract.

apps/desktop/src/lib/file-operations/transfer/TransferDialog.svelte

@@ -541,23 +541,23 @@
             <div class="conflict-policy">
                 <label class="policy-option">
                     <input type="radio" bind:group={conflictPolicy} value="skip" />
-                    <span>Skip all</span>
+                    <span>{totalConflictCount === 1 ? 'Skip' : 'Skip all'}</span>
                 </label>
                 <label class="policy-option">
                     <input type="radio" bind:group={conflictPolicy} value="overwrite" />
-                    <span>Overwrite all</span>
+                    <span>{totalConflictCount === 1 ? 'Overwrite' : 'Overwrite all'}</span>
                 </label>
                 <label class="policy-option">
                     <input type="radio" bind:group={conflictPolicy} value="overwrite_smaller" />
-                    <span>Overwrite all smaller</span>
+                    <span>{totalConflictCount === 1 ? 'Overwrite if smaller' : 'Overwrite all smaller'}</span>
                 </label>
                 <label class="policy-option">
                     <input type="radio" bind:group={conflictPolicy} value="overwrite_older" />
-                    <span>Overwrite all older</span>
+                    <span>{totalConflictCount === 1 ? 'Overwrite if older' : 'Overwrite all older'}</span>
                 </label>
                 <label class="policy-option">
                     <input type="radio" bind:group={conflictPolicy} value="stop" />
-                    <span>Ask for each</span>
+                    <span>{totalConflictCount === 1 ? 'Ask later' : 'Ask for each'}</span>
                 </label>
             </div>
         </div>