feat: web_read (trafilatura), session_read, http_fetch max_chars

web_read(url, max_chars=16000) — fetches a URL and extracts clean article
text via trafilatura, stripping ads/nav/boilerplate. Returns markdown.

session_read(date) — reads a full session log by YYYY-MM-DD date; lists
available dates if the requested one is not found.

http_fetch gains a max_chars param (default 8192, max 32768) so the cap
is configurable instead of hardcoded.

Tool count: 45 → 47.

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

cortex/tools/files.py

@@ -230,6 +230,34 @@ def _sync_file_write(path: str, content: str, mode: str) -> str:
 _SEARCH_EXCERPT_CHARS = 150
 
 
+async def session_read(date: str) -> str:
+    """Read a full session log by date (YYYY-MM-DD).
+
+    Returns the complete session log for that date. If the date is not found,
+    lists the most recent available dates instead.
+    Only reads the current user's own sessions (per-persona isolation via ContextVars).
+    """
+    return await asyncio.to_thread(_sync_session_read, date.strip())
+
+
+def _sync_session_read(date: str) -> str:
+    from persona import persona_path
+    sessions_dir = persona_path() / "sessions"
+    if not sessions_dir.exists():
+        return "No session logs found."
+
+    target = sessions_dir / f"{date}.md"
+    if target.exists():
+        content = target.read_text()
+        return f"Session log for {date} ({len(content)} chars):\n\n{content}"
+
+    available = sorted([f.stem for f in sessions_dir.glob("*.md")], reverse=True)
+    if not available:
+        return "No session logs found."
+    recent = "\n".join(f"  {d}" for d in available[:15])
+    return f"No session log found for '{date}'. Available dates (most recent first):\n{recent}"
+
+
 async def session_search(query: str, limit: int = 5) -> str:
     """Search past session logs for a keyword or phrase.
 
@@ -329,6 +357,22 @@ DECLARATIONS = [
             required=["path", "content"],
         ),
     ),
+    types.FunctionDeclaration(
+        name="session_read",
+        description=(
+            "Read a full session log by date (YYYY-MM-DD). Returns the complete conversation "
+            "from that session — useful for continuity, recalling decisions, or reviewing "
+            "what was discussed on a specific day. If the date is not found, lists available dates. "
+            "Only reads this user's own sessions."
+        ),
+        parameters=types.Schema(
+            type=types.Type.OBJECT,
+            properties={
+                "date": types.Schema(type=types.Type.STRING, description="Date in YYYY-MM-DD format (e.g. '2026-05-08')"),
+            },
+            required=["date"],
+        ),
+    ),
     types.FunctionDeclaration(
         name="session_search",
         description=(