Project-aware assist, link suggestions, project-scoped RAG, semantic search tool, SSE race fix

- Writing assistant: inject project notes as context (definition-tagged first), wikilink suggestions
- Link suggestions: server-side endpoint finds unlinked term occurrences, NoteEditorView sidebar panel
- Project-scoped RAG: ChatView ProjectSelector filters semantic+keyword search to selected project
- Semantic search tool: LLM search_notes upgraded to hybrid semantic (0.40 threshold) + keyword merge
- SSE race condition fix: drain remaining events after stream loop exits in chat.py and notes.py
- RAG_AUTO_SNIPPET raised 800→4000; sidebar include uses full note body; MAX_BODY_CHARS 8000→24000
- Enter-to-submit on writing assistant instruction textareas (note and task editors)
- DiffView: equal-line collapsing with 3-line context around changes

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

src/fabledassistant/services/llm.py

@@ -1,11 +1,14 @@
 import asyncio
+import ipaddress
 import json
 import logging
 import re
+import socket
 import time
 from collections.abc import AsyncGenerator
 from dataclasses import dataclass, field
 from typing import Literal
+from urllib.parse import urlparse
 
 import httpx
 
@@ -29,7 +32,7 @@ STOP_WORDS = frozenset({
 
 RAG_AUTO_THRESHOLD = 0.60
 RAG_AUTO_LIMIT = 3
-RAG_AUTO_SNIPPET = 800
+RAG_AUTO_SNIPPET = 4000
 
 
 async def get_installed_models() -> set[str]:
@@ -268,11 +271,32 @@ async def generate_completion(
     raise last_exc
 
 
+def _is_private_url(url: str) -> bool:
+    """Return True if the URL resolves to a private/loopback/link-local address (SSRF guard)."""
+    try:
+        host = urlparse(url).hostname
+        if not host:
+            return True
+        if host.lower() in ("localhost", "::1"):
+            return True
+        addr_info = socket.getaddrinfo(host, None, proto=socket.IPPROTO_TCP)
+        for entry in addr_info:
+            ip = ipaddress.ip_address(entry[4][0])
+            if ip.is_private or ip.is_loopback or ip.is_link_local or ip.is_reserved or ip.is_multicast:
+                return True
+        return False
+    except Exception:
+        return True  # Block on resolution failure
+
+
 async def fetch_url_content(url: str) -> str:
     """Fetch a URL and return text content (HTML tags stripped)."""
+    if _is_private_url(url):
+        logger.warning("Blocked fetch of private/internal URL: %s", url)
+        return "[URL blocked: internal network access not permitted]"
     try:
         async with httpx.AsyncClient(
-            timeout=15.0, follow_redirects=True, headers={"User-Agent": "FabledAssistant/1.0"}
+            timeout=15.0, follow_redirects=False, headers={"User-Agent": "FabledAssistant/1.0"}
         ) as client:
             resp = await client.get(url)
             resp.raise_for_status()
@@ -426,6 +450,7 @@ async def build_context(
     history_summary: str | None = None,
     include_note_ids: list[int] | None = None,
     excluded_note_ids: list[int] | None = None,
+    rag_project_id: int | None = None,
 ) -> tuple[list[dict], dict]:
     """Build messages array for Ollama with system prompt and context.
 
@@ -465,6 +490,9 @@ async def build_context(
         "If a note was created earlier in the conversation and the user provides more content for it, use update_note. "
         "Use get_note to read the full content of a specific note. "
         "Use list_notes to browse notes by recency or tag. "
+        "Use search_notes for conceptual/semantic queries — e.g. 'what notes do I have about X' or "
+        "'find notes related to Y' — it uses semantic understanding to find thematically related content "
+        "even when exact words don't match. Pass project= to scope the search to a specific project. "
         "Use delete_note / delete_task only when explicitly asked to delete — these require confirmation."
     )
     tool_guidance = "\n".join(tool_lines)
@@ -511,7 +539,8 @@ async def build_context(
     try:
         from fabledassistant.services.embeddings import semantic_search_notes
         for score, note in await semantic_search_notes(
-            user_id, user_message, exclude_ids=search_exclude or None, limit=8
+            user_id, user_message, exclude_ids=search_exclude or None, limit=8,
+            project_id=rag_project_id,
         ):
             found_scored.append((score, note))
     except Exception:
@@ -522,7 +551,8 @@ async def build_context(
         if keywords:
             try:
                 for note in await search_notes_for_context(
-                    user_id, keywords, exclude_ids=search_exclude or None, limit=8
+                    user_id, keywords, exclude_ids=search_exclude or None, limit=8,
+                    project_id=rag_project_id,
                 ):
                     found_scored.append((None, note))
             except Exception:
@@ -587,7 +617,7 @@ async def build_context(
             try:
                 n = await _get_note(user_id, nid)
                 if n:
-                    body_preview = n.body[:2000] if n.body else ""
+                    body_preview = n.body or ""
                     included_snippets.append(f"- {n.title}: {body_preview}")
             except Exception:
                 logger.warning("Failed to load included note %d for context", nid, exc_info=True)