Replace static buffer with dynamic allocation in writercwtdata()

## Description
The `writercwtdata()` function in `src/lib_ccx/output.c` currently uses a static array for the `cbbuffer` variable. There's a TODO comment requesting to replace this with dynamic memory allocation using `malloc`.

**File:** `src/lib_ccx/output.c`
**Line:** ~156
**Function:** `writercwtdata()`

## Current Implementation
```c
static unsigned char cbbuffer[0xFFFF * 3]; // TODO: use malloc
```

## Proposed Change
Replace the static array with dynamically allocated memory to:
- Improve memory efficiency
- Follow modern C best practices
- Only allocate memory when the function is actually used

## Benefits
1. Memory is only allocated when needed
2. Better resource management
3. Maintains backward compatibility
4. No change to external behavior

## Implementation Plan
I'm working on a PR that will:
1. Convert `cbbuffer` from static array to dynamically allocated pointer
2. Allocate memory on first use of the function
3. Add proper error handling for allocation failures
4. Add debug logging for buffer allocation