Add full AXL parity implementation plan (16 phases, ~1,068 operations)

Covers all resource types from CUCM AXL WSDL v15.0 organized by priority:
Phase 1: Hunt groups, call parking/pickup, app users, device actions
Phase 2: Device config templates (phone button, security, softkey, SIP profiles)
Phase 3: Infrastructure (locations, regions, media resources, DHCP, SRST)
Phase 4: Extended dial plan (transformations, route filters, time-based routing)
Phase 5-16: LDAP, mobility, voicemail, H323, VPN, presence, WiFi, IME, CCD/SAF

Each phase lists resource types, target files, key fields, and CLI command names.
Includes implementation notes: XSD lookup commands, member XML patterns, testing steps.

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

Author: mycollablab

CLAUDE.md

@@ -1,5 +1,10 @@
 # CUCM CLI — Development Guide
 
+## Full Parity Implementation Plan
+
+See **`IMPLEMENTATION_PLAN.md`** for the phased plan to reach full AXL parity.
+Current coverage: ~66 of 1,068 WSDL operations. Start with Phase 1.
+
 ## Project Layout
 
 ```