Revert context note truncation — preserve full note content

Pinned note: full body restored (truncation is wrong when the user is
explicitly asking about that note's content).
Auto-notes: restored to 2000 chars (800 was too restrictive for useful context).

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

src/fabledassistant/services/llm.py

@@ -289,20 +289,16 @@ async def build_context(
         "auto_notes": [],
     }
 
-    # Include current note context if provided (cap at 4000 chars — explicitly selected
-    # so more generous, but very long notes would blow up the prefill phase)
+    # Include current note context if provided — full body, no truncation
     if current_note_id:
         note = await get_note(user_id, current_note_id)
         if note:
             context_meta["context_note_id"] = note.id
             context_meta["context_note_title"] = note.title
-            body = note.body or ""
-            truncated = body[:4000]
-            suffix = "\n[...truncated]" if len(body) > 4000 else ""
             system_parts.append(
                 f"\n\n--- Current Note ---\n"
                 f"Title: {note.title}\n"
-                f"Content:\n{truncated}{suffix}\n"
+                f"Content:\n{note.body}\n"
                 f"--- End Note ---"
             )
 
@@ -318,9 +314,7 @@ async def build_context(
             )
             snippets: list[str] = []
             for n in notes:
-                # 800 chars keeps context meaningful without bloating the prefill phase.
-                # The user can ask follow-up questions for more detail.
-                body_preview = n.body[:800] if n.body else ""
+                body_preview = n.body[:2000] if n.body else ""
                 snippets.append(f"- {n.title}: {body_preview}")
                 context_meta["auto_notes"].append({"id": n.id, "title": n.title})
             if snippets: