v1.9.0 -> v1.10.0: file upload UI + attachment management

- Paperclip icon left of text input, file preview pill (image thumb or file icon)
- Conversation list shows attachment icon right of trash, opens gallery overlay
- Gallery overlay: scrollable, close (X), delete attachment per item
- DELETE /api/upload/{id} removes from SQLite + Qdrant
- PATCH /api/upload/{id}/link ties upload to conversation
- GET /api/upload/by-conversation/{id} lists attachments
- Chat accepts upload_context_id, injects [ATTACHED DOCUMENT] into system prompt
- Conversation list includes attachment_count field
- 8 new tests: upload context injection, delete, link, by-conversation, image type, attachment count

Still missing (P3): drag-and-drop upload, global attachments page, file download, batch upload

config.py

@@ -9,7 +9,7 @@ import logging
 
 log = logging.getLogger("jarvischat")
 
-VERSION = "v1.9.0"
+VERSION = "v1.10.0"
 OLLAMA_BASE = os.environ.get("OLLAMA_BASE", "http://localhost:11434")
 LLAMA_SERVER_BASE = os.environ.get("LLAMA_SERVER_BASE", "http://192.168.50.108:8081")
 SEARXNG_BASE = "http://localhost:8888"
@@ -49,7 +49,7 @@ BODY_LIMIT_PROFILE_BYTES = 256 * 1024
 # --- Upload ---
 UPLOAD_DIR = "/tmp/jarvischat_uploads"
 MAX_UPLOAD_BYTES = 20 * 1024 * 1024
-SUPPORTED_UPLOAD_TYPES = {"text/plain", "text/markdown", "application/pdf", "application/json", "text/x-python", "text/html"}
+SUPPORTED_UPLOAD_TYPES = {"text/plain", "text/markdown", "application/pdf", "application/json", "text/x-python", "text/html", "image/png", "image/jpeg", "image/gif", "image/svg+xml", "image/webp"}
 UPLOAD_CONTEXT_EXPIRY_HOURS = 1
 BODY_LIMIT_UPLOAD_BYTES = MAX_UPLOAD_BYTES