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/assist.py

@@ -1,18 +1,50 @@
-MAX_BODY_CHARS = 8000
+MAX_BODY_CHARS = 24000
+MAX_CONTEXT_NOTE_CHARS = 1500
+
+
+def _build_context_block(context_notes: list[dict]) -> str:
+    """Format project context notes into a prompt block."""
+    lines = [
+        "--- Project Context ---",
+        "The following notes are from the same project. Notes tagged 'definition' are "
+        "canonical term definitions — treat them as authoritative. Use them to maintain "
+        "consistency in terminology, tone, style, and [[wikilinks]] to other documents.",
+        "",
+    ]
+    for n in context_notes:
+        tags_str = f"  [tags: {', '.join(n['tags'])}]" if n.get("tags") else ""
+        body_preview = (n["body"] or "")[:MAX_CONTEXT_NOTE_CHARS]
+        if len(n["body"] or "") > MAX_CONTEXT_NOTE_CHARS:
+            body_preview += "…"
+        lines.append(f"**{n['title']}**{tags_str}")
+        if body_preview:
+            lines.append(body_preview)
+        lines.append("")
+    lines.append("--- End Project Context ---")
+    return "\n".join(lines)
 
 
 def build_assist_messages(
-    body: str, target_section: str, instruction: str, whole_doc: bool = False
+    body: str,
+    target_section: str,
+    instruction: str,
+    whole_doc: bool = False,
+    context_notes: list[dict] | None = None,
 ) -> list[dict]:
     """Build Ollama messages for writing assist.
 
     When whole_doc=True, the model revises the entire document.
     When whole_doc=False (section mode), the full body is provided as read-only
     context and the model outputs only the replacement for the target section.
+
+    context_notes: optional list of {title, tags, body} dicts from the same project,
+    injected so the model can maintain consistency with related documents.
     """
     truncated_body = body[:MAX_BODY_CHARS]
     if len(body) > MAX_BODY_CHARS:
-        truncated_body += "\n... (truncated)"
+        truncated_body += "\n… (truncated)"
+
+    context_block = (_build_context_block(context_notes) + "\n\n") if context_notes else ""
 
     if whole_doc:
         system_content = (
@@ -21,9 +53,12 @@ def build_assist_messages(
             "content not addressed by the instruction. "
             "Preserve all markdown formatting exactly — including bullet lists (- item), "
             "numbered lists (1. item), nested/indented sub-items (  - sub), bold (**text**), "
-            "italic (_text_), and code blocks. Never flatten nested lists into plain text."
+            "italic (_text_), and code blocks. Never flatten nested lists into plain text. "
+            "When referencing concepts defined in the Project Context, use [[wikilinks]] "
+            "to link to the relevant note by its exact title."
         )
         user_content = (
+            f"{context_block}"
             f"--- Document ---\n{truncated_body}\n--- End Document ---\n\n"
             f"Instruction: {instruction}"
         )
@@ -41,9 +76,12 @@ def build_assist_messages(
             "Match the document's existing tone and style. "
             "IMPORTANT: Preserve all markdown formatting exactly — including bullet lists (- item), "
             "numbered lists (1. item), nested/indented sub-items (  - sub), bold (**text**), "
-            "italic (_text_), and code blocks. Never flatten nested lists into plain text."
+            "italic (_text_), and code blocks. Never flatten nested lists into plain text. "
+            "When referencing concepts defined in the Project Context, use [[wikilinks]] "
+            "to link to the relevant note by its exact title."
         )
         user_content = (
+            f"{context_block}"
             f"--- Target Section ---\n{target_section}\n--- End Target Section ---\n\n"
             f"Instruction: {instruction}"
         )