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>

ROADMAP.md

@@ -39,7 +39,7 @@
 - [x] Admin/owner permission system (hostmask + IRCOP)
 - [x] !whoami and !admins commands
 
-## v0.4.0 -- Wave 3 Plugins (Local Databases) (current)
+## v0.4.0 -- Wave 3 Plugins (Local Databases) (done)
 
 - [ ] GeoIP plugin (MaxMind GeoLite2-City mmdb)
 - [ ] ASN plugin (GeoLite2-ASN mmdb)
@@ -48,12 +48,12 @@
 - [ ] CVE lookup plugin (local NVD JSON feed)
 - [ ] Data update script (cron-friendly, all local DBs)
 
-## v0.5.0 -- Wave 4 Plugins (Advanced)
+## v0.5.0 -- Wave 4 Plugins (Advanced) (current)
 
-- [ ] Operational logging plugin (SQLite per-channel)
-- [ ] Persistent notes plugin (per-channel key-value)
-- [ ] Subdomain enumeration (crt.sh + wordlist DNS brute)
-- [ ] HTTP header fingerprinting (local signature db)
+- [x] Operational logging plugin (SQLite per-channel)
+- [x] Persistent notes plugin (per-channel key-value)
+- [x] Subdomain enumeration (crt.sh + wordlist DNS brute)
+- [x] HTTP header fingerprinting (local signature db)
 - [ ] ExploitDB search (local CSV clone)
 - [ ] Payload template library (SQLi, XSS, SSTI)