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>

docs/CHEATSHEET.md

@@ -86,6 +86,25 @@ IRC operators are auto-detected via WHO. Hostmask patterns use fnmatch.
 !cert example.com       # CT log lookup (max 5 domains)
 !whois example.com      # WHOIS domain lookup
 !whois 8.8.8.8          # WHOIS IP lookup
+!subdomain example.com        # CT log subdomain enum
+!subdomain example.com brute  # + DNS wordlist brute
+!headers example.com          # HTTP fingerprint (tech + security)
+```
+
+## Ops
+
+```
+!opslog add Compromised target  # Add timestamped entry
+!opslog list                    # Show last 5 entries
+!opslog list 10                 # Show last 10
+!opslog search pivot            # Search entries
+!opslog del 3                   # Delete entry by ID
+!opslog clear                   # Clear channel log (admin)
+!note set target 10.0.0.1      # Store a note
+!note get target                # Retrieve a note
+!note del target                # Delete a note
+!note list                      # List all keys
+!note clear                     # Clear all notes (admin)
 ```
 
 ## Red Team