docs: Update CHANGELOG with Sprint 3+4 features and stability fixes

Added:
- Symbol CRUD operations (create/rename/delete/imports/exports)
- Bookmark management tools
- Enum and typedef creation
- Variable management (list/rename/functions_variables)
- Namespace and class tools
- Memory segment tools

Changed:
- Docker port allocation now auto-allocated from pool (8192-8223)
- docker_auto_start defaults to wait=False

Fixed:
- instances_use hanging (lazy registration pattern)
- Event loop blocking in docker_health (run_in_executor)
- Session isolation for docker_stop/docker_cleanup
- Background discovery thread timeout (30s → 0.5s)
- Typedef/variable type resolution

CHANGELOG.md

@@ -7,6 +7,30 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ## [Unreleased]
 
 ### Added
+- **Symbol CRUD Operations:** Full create/rename/delete support for symbols and labels:
+  - `symbols_create` - Create new label/symbol at an address
+  - `symbols_rename` - Rename existing symbol
+  - `symbols_delete` - Delete symbol at an address
+  - `symbols_imports` - List imported symbols with pagination
+  - `symbols_exports` - List exported symbols with pagination
+- **Bookmark Management:** Tools for managing Ghidra bookmarks:
+  - `bookmarks_list` - List bookmarks with type/category filtering
+  - `bookmarks_create` - Create bookmark at address (Note, Warning, Error, Info types)
+  - `bookmarks_delete` - Delete bookmarks at an address
+- **Enum & Typedef Creation:** Data type creation tools:
+  - `enums_create` - Create new enum data type
+  - `enums_list` - List enum types with members
+  - `typedefs_create` - Create new typedef
+  - `typedefs_list` - List typedef data types
+- **Variable Management:** Enhanced variable operations:
+  - `variables_list` - List variables with global_only filter
+  - `variables_rename` - Rename and retype function variables
+  - `functions_variables` - List local variables and parameters for a function
+- **Namespace & Class Tools:**
+  - `namespaces_list` - List all non-global namespaces
+  - `classes_list` - List class namespaces with qualified names
+- **Memory Segment Tools:**
+  - `segments_list` - List memory segments with R/W/X permissions and size info
 - **Progress Reporting for Long Operations:** 7 MCP prompts now report real-time progress during multi-step scanning operations:
   - `malware_triage` - Reports progress across 21 scanning steps
   - `analyze_imports` - Reports progress across 12 capability categories
@@ -33,6 +57,17 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
   - `document_struct` - Comprehensively document data structure fields and usage
   - `find_error_handlers` - Map error handling, cleanup routines, and exit paths
 
+### Changed
+- **Docker Port Allocation:** Ports are now auto-allocated from pool (8192-8223) instead of client-specified. Prevents session collisions in multi-agent environments.
+- **docker_auto_start:** Default `wait=False` for immediate return. Use `docker_wait` separately to poll for container readiness.
+
+### Fixed
+- **instances_use Hanging:** Eliminated 4+ hour hangs by removing blocking HTTP call. Now uses lazy registration — just creates a stub entry, validates on first real tool call.
+- **Event Loop Blocking:** `docker_health` now runs HTTP checks in thread executor via `run_in_executor()`, preventing MCP server freeze during health polling.
+- **Session Isolation:** `docker_stop` now validates container belongs to current session before stopping. `docker_cleanup` defaults to `session_only=True` to prevent cross-session interference.
+- **Background Discovery Thread:** Fixed timeout from 30s to 0.5s for port scanning, reducing discovery cycle from 300s+ to ~15s.
+- **Typedef/Variable Type Resolution:** Fixed `handle_typedef_create` and `handle_variable_rename` to use shared `resolve_data_type()` for builtin types (int, char, etc.).
+
 ## [2025.12.1] - 2025-12-01
 
 ### Added