feat: add wave 4 plugins (opslog, note, subdomain, headers)

Opslog: timestamped operational log per channel with add, list,
search, and delete. SQLite-backed, admin-only clear.

Note: persistent per-channel key-value store with set, get, del,
list, clear. SQLite-backed, admin-only clear.

Subdomain: enumeration via crt.sh CT log query with optional DNS
brute force using a built-in 80-word prefix wordlist. Resolves
discovered subdomains concurrently.

Headers: HTTP header fingerprinting against 50+ signature patterns.
Detects servers, frameworks, CDNs, and security headers (HSTS, CSP,
XFO, etc).

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

plugins/opslog.py

@@ -0,0 +1,140 @@
+"""Plugin: timestamped operational log (SQLite per-channel)."""
+
+from __future__ import annotations
+
+import logging
+import sqlite3
+from datetime import datetime, timezone
+from pathlib import Path
+
+from derp.plugin import command
+
+log = logging.getLogger(__name__)
+
+_DB_PATH = Path("data/opslog.db")
+_MAX_LIST = 10
+_MAX_SEARCH = 10
+
+_conn: sqlite3.Connection | None = None
+
+
+def _db() -> sqlite3.Connection:
+    """Lazy-init the database connection and schema."""
+    global _conn
+    if _conn is not None:
+        return _conn
+    _DB_PATH.parent.mkdir(parents=True, exist_ok=True)
+    _conn = sqlite3.connect(str(_DB_PATH))
+    _conn.execute("""
+        CREATE TABLE IF NOT EXISTS entries (
+            id       INTEGER PRIMARY KEY AUTOINCREMENT,
+            channel  TEXT NOT NULL,
+            nick     TEXT NOT NULL,
+            ts       TEXT NOT NULL,
+            message  TEXT NOT NULL
+        )
+    """)
+    _conn.execute("CREATE INDEX IF NOT EXISTS idx_entries_channel ON entries(channel)")
+    _conn.commit()
+    return _conn
+
+
+@command("opslog", help="Op log: !opslog add|list|search|del|clear")
+async def cmd_opslog(bot, message):
+    """Timestamped operational log per channel.
+
+    Usage:
+        !opslog add <text>          Add a log entry
+        !opslog list [n]            Show last n entries (default 5)
+        !opslog search <term>       Search entries
+        !opslog del <id>            Delete an entry
+        !opslog clear               Clear all entries for this channel (admin)
+    """
+    parts = message.text.split(None, 2)
+    if len(parts) < 2:
+        await bot.reply(message, "Usage: !opslog <add|list|search|del|clear> [args]")
+        return
+
+    sub = parts[1].lower()
+    rest = parts[2] if len(parts) > 2 else ""
+    channel = message.target or "dm"
+
+    if sub == "add":
+        if not rest:
+            await bot.reply(message, "Usage: !opslog add <text>")
+            return
+        ts = datetime.now(timezone.utc).strftime("%Y-%m-%d %H:%M")
+        db = _db()
+        cur = db.execute(
+            "INSERT INTO entries (channel, nick, ts, message) VALUES (?, ?, ?, ?)",
+            (channel, message.nick or "?", ts, rest),
+        )
+        db.commit()
+        await bot.reply(message, f"[{cur.lastrowid}] logged")
+
+    elif sub == "list":
+        limit = _MAX_LIST
+        if rest:
+            try:
+                limit = min(int(rest), _MAX_LIST)
+            except ValueError:
+                pass
+        db = _db()
+        rows = db.execute(
+            "SELECT id, nick, ts, message FROM entries WHERE channel = ? "
+            "ORDER BY id DESC LIMIT ?",
+            (channel, limit),
+        ).fetchall()
+        if not rows:
+            await bot.reply(message, "No entries")
+            return
+        for row_id, nick, ts, msg in reversed(rows):
+            await bot.reply(message, f"[{row_id}] {ts} <{nick}> {msg}")
+
+    elif sub == "search":
+        if not rest:
+            await bot.reply(message, "Usage: !opslog search <term>")
+            return
+        db = _db()
+        rows = db.execute(
+            "SELECT id, nick, ts, message FROM entries "
+            "WHERE channel = ? AND message LIKE ? ORDER BY id DESC LIMIT ?",
+            (channel, f"%{rest}%", _MAX_SEARCH),
+        ).fetchall()
+        if not rows:
+            await bot.reply(message, f"No entries matching '{rest}'")
+            return
+        for row_id, nick, ts, msg in reversed(rows):
+            await bot.reply(message, f"[{row_id}] {ts} <{nick}> {msg}")
+
+    elif sub == "del":
+        if not rest:
+            await bot.reply(message, "Usage: !opslog del <id>")
+            return
+        try:
+            entry_id = int(rest)
+        except ValueError:
+            await bot.reply(message, "Invalid ID")
+            return
+        db = _db()
+        cur = db.execute(
+            "DELETE FROM entries WHERE id = ? AND channel = ?",
+            (entry_id, channel),
+        )
+        db.commit()
+        if cur.rowcount:
+            await bot.reply(message, f"Deleted entry {entry_id}")
+        else:
+            await bot.reply(message, f"Entry {entry_id} not found")
+
+    elif sub == "clear":
+        if not bot._is_admin(message):
+            await bot.reply(message, "Permission denied: clear requires admin")
+            return
+        db = _db()
+        cur = db.execute("DELETE FROM entries WHERE channel = ?", (channel,))
+        db.commit()
+        await bot.reply(message, f"Cleared {cur.rowcount} entries")
+
+    else:
+        await bot.reply(message, "Usage: !opslog <add|list|search|del|clear> [args]")