fix(system): read the database size the report sends

The Database line read database_info.size_bytes, a key the report does
not have (get_database_info answers database_size_bytes), so it always
read "Readable · 0 bytes · N images". The browser test now requires a
non-zero size. Found by PR 3's concept comparison.

Part of #329

tests/browser/workspace-system-diagnostics.spec.mjs

@@ -123,6 +123,9 @@ test('meta-grid shows real database and source status, the pinned Viewer.js vers
         await expect(surface.locator('.meta-grid dt')).toHaveText(['Database', 'Sources', 'Viewer.js', 'Host renderers']);
         const images = report.checks.database.image_count;
         await expect(cell(page, 'Database')).toHaveText(new RegExp(`^Readable · [\\d.]+ (bytes|KB|MB|GB) · ${images.toLocaleString('en-US')} images?$`));
+        // The size is the database's real size (`database_size_bytes`), never a missing key read as 0.
+        expect(report.database_info.database_size_bytes).toBeGreaterThan(0);
+        await expect(cell(page, 'Database')).not.toContainText('· 0 bytes ·');
         const { configured, watching } = report.sources;
         await expect(cell(page, 'Sources')).toHaveText(configured
             ? `${configured} source${configured === 1 ? '' : 's'} · ${watching} watching`

tests/js/workspace-system-diagnostics.test.js

@@ -14,7 +14,7 @@ const SYSTEM = fs.readFileSync(path.join(__dirname, '../../web/js/workspace/syst
 
 const REPORT = {
     checks: { database: { status: 'ok', prompt_count: 4210, has_images_table: true, image_count: 19956 } },
-    database_info: { database_path: 'user/__promptmanager/prompts.db', size_bytes: 1717986918 },
+    database_info: { database_path: 'user/__promptmanager/prompts.db', database_size_bytes: 1717986918 },
     sources: { configured: 2, effective: 2, watching: 2, unavailable: 0 },
     viewerjs: '1.15.2',
 };
@@ -45,7 +45,7 @@ test('database text covers readable, not readable, busy and loading', async () =
     const { databaseText, LOADING, UNREADABLE } = await diagnostics;
     assert.equal(databaseText({ report: REPORT }), 'Readable · 1.6 GB · 19,956 images');
     assert.equal(databaseText({ report: { ...REPORT, checks: { database: { status: 'ok', image_count: 1 } },
-        database_info: { size_bytes: 2048 } } }), 'Readable · 2.0 KB · 1 image');
+        database_info: { database_size_bytes: 2048 } } }), 'Readable · 2.0 KB · 1 image');
     assert.equal(databaseText({ report: { checks: { database: { status: 'error', message: 'Database error: locked' } } } }),
         'Not readable: Database error: locked');
     assert.equal(databaseText({ loading: true }), LOADING);

web/js/workspace/system-diagnostics.mjs

@@ -114,7 +114,7 @@ export function databaseText(state) {
         const check = report?.checks?.database;
         if (check?.status !== 'ok') return `Not readable: ${check?.message || 'no answer from the database'}`;
         const images = Number.isSafeInteger(check.image_count) ? check.image_count : 0;
-        return `Readable · ${sizeText(report.database_info?.size_bytes)} · ${number(images)} ${noun(images, 'image')}`;
+        return `Readable · ${sizeText(report.database_info?.database_size_bytes)} · ${number(images)} ${noun(images, 'image')}`;
     });
 }