chore: add v0.4.8 changelog and improve scroll behavior (#234)

* chore: add v0.4.8 changelog and improve scroll behavior

- Add v0.4.8 changelog entries for recent fixes
- Fix forced scroll to bottom when returning from other tabs
- Smooth session switch with loading transition overlay
- Auto-scroll to bottom after mermaid diagram rendering
- Bump version to 0.4.8

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: replace blob URLs with persistent download URLs and add image preview

- Replace blob URLs with /api/hermes/download URLs after upload so
  attachments survive page refresh
- Add click-to-preview overlay for image attachments
- Move upload directory from /tmp to ~/.hermes-web-ui/upload

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* fix: replace findLast with reverse+find for ES2022 compat

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* chore: bump TypeScript lib target from ES2022 to ES2023

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: add changelog entries for blob URL fix, image preview and upload dir

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

packages/server/src/config.ts

@@ -1,10 +1,10 @@
 import { resolve } from 'path'
-import { tmpdir } from 'os'
+import { homedir } from 'os'
 
 export const config = {
   port: parseInt(process.env.PORT || '8648', 10),
   upstream: process.env.UPSTREAM || 'http://127.0.0.1:8642',
-  uploadDir: process.env.UPLOAD_DIR || resolve(tmpdir(), 'hermes-uploads'),
+  uploadDir: process.env.UPLOAD_DIR || resolve(homedir(), '.hermes-web-ui', 'upload'),
   dataDir: resolve(__dirname, '..', 'data'),
   corsOrigins: process.env.CORS_ORIGINS || '*',
 }