fix: batch tag queries, inline edit, delete response, SPA catch-all, link glyph

- Fix N+1 tag query in List() with batched IN clause
- Add inline body editing in web detail pane (dblclick or e key)
- Delete API returns {result: "soft"|"hard"} with 200 instead of 204
- SPA handler serves index.html for all extensionless paths
- Link glyph changed from emoji 🔗 to unicode ↗ for terminal alignment
- Capture bar contrast and hover glow increased
- Comment on load-bearing "--" in root.go

web/index.html

@@ -51,7 +51,7 @@
                     <span>decision</span>
                 </button>
                 <button data-type="link" class="type-btn">
-                    <span class="type-glyph">🔗</span>
+                    <span class="type-glyph">↗</span>
                     <span>link</span>
                 </button>
             </div>