ux(classifier): relabel the two JSON surfaces so their purpose is clear

Two exports for two different consumers were both just "Export". Name them:
- Classification (header, AI round-trip): "Export for editing" / "Import edits"
  — a filename-per-file JSON with no scanned tree, meant to be hand/AI-edited
  and re-imported. Download suffix is now .zddc-classification.json.
- Workspace (welcome screen, transfer/backup): "Import workspace" + a row
  "Export" tooltip spelling out it carries the snapshot + classifications for
  moving between browsers. Download suffix stays .zddc-workspace.json.
Each tooltip points at the other so they're not confused.

Also wire workspace.activeName (referenced by the dataset export but never
exported), so a classification file is named after its workspace.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

classifier/js/app.js

@@ -259,7 +259,7 @@
         var url = URL.createObjectURL(blob);
         var a = document.createElement('a');
         a.href = url;
-        a.download = String(name).replace(/[^\w.-]+/g, '_') + '.json';
+        a.download = String(name).replace(/[^\w.-]+/g, '_') + '.zddc-classification.json';
         document.body.appendChild(a); a.click(); a.remove();
         URL.revokeObjectURL(url);
     }

classifier/js/workspace.js

@@ -108,10 +108,15 @@
 
         var actions = document.createElement('div');
         actions.className = 'ws-row__actions';
+        var titles = {
+            export: 'Export this whole workspace (scanned snapshot + classifications) to transfer to another browser or back up',
+            delete: 'Delete this workspace — your source files are untouched',
+        };
         [['open', 'Open'], ['rename', 'Rename'], ['export', 'Export'], ['delete', 'Delete']].forEach(function (a) {
             var b = document.createElement('button');
             b.className = 'btn btn-sm ' + (a[0] === 'open' ? 'btn-primary' : 'btn-secondary');
             b.dataset.act = a[0]; b.textContent = a[1];
+            if (titles[a[0]]) b.title = titles[a[0]];
             actions.appendChild(b);
         });
         row.appendChild(main); row.appendChild(actions);
@@ -374,5 +379,6 @@
         onRescanned: onRescanned,
         renderList: renderList,
         activeId: function () { return activeId; },
+        activeName: function () { return activeMeta ? activeMeta.name : null; },
     };
 })();

classifier/template.html

@@ -162,8 +162,8 @@
                         <div class="pane-header-right">
                             <span id="classifyStats" class="file-stats"></span>
                             <span class="header-divider">|</span>
-                            <button id="exportDatasetBtn" class="btn btn-secondary btn-sm" title="Export the classification dataset (trees + assignments) as JSON">Export</button>
+                            <button id="exportDatasetBtn" class="btn btn-secondary btn-sm" title="Download the classifications as a filename-per-file JSON to edit (e.g. with an AI), then re-import here. NOT a workspace — no scanned tree.">Export for editing</button>
-                            <button id="importDatasetBtn" class="btn btn-secondary btn-sm" title="Import a classification dataset JSON (replaces the current one)">Import</button>
+                            <button id="importDatasetBtn" class="btn btn-secondary btn-sm" title="Load an edited classification JSON back in — replaces the current classifications. (To move a whole scanned workspace between browsers, use “Import workspace” on the welcome screen.)">Import edits</button>
                             <input type="file" id="importDatasetInput" accept="application/json,.json" hidden>
                             <button id="resetDatasetBtn" class="btn btn-sm btn-danger" title="Discard all classifications and start over from the raw scanned input (does not touch your files)">Reset</button>
                             <button id="copyOutputBtn" class="btn btn-primary btn-sm" disabled title="Copy mapped files to an output directory (source untouched)">Copy…</button>
@@ -209,7 +209,7 @@
                         <div class="ws-head">
                             <h2>Your workspaces</h2>
                             <div class="ws-head__actions">
-                                <button id="importWorkspaceBtn" class="btn btn-secondary" title="Import a workspace exported from another browser (.json) — restores the scanned snapshot so you don't re-scan">⭱ Import</button>
+                                <button id="importWorkspaceBtn" class="btn btn-secondary" title="Import a whole workspace (.zddc-workspace.json) exported from another browser — restores the scanned snapshot so you don't re-scan">⭱ Import workspace</button>
                                 <button id="newWorkspaceBtn" class="btn btn-primary">+ New workspace</button>
                             </div>
                             <input type="file" id="importWorkspaceInput" accept="application/json,.json" hidden>