chore: Make hardcoded values configurable

[nnennandukwe]

Summary

Several parameters are hardcoded throughout the codebase. These should be configurable for different use cases and environments.

Hardcoded Values

Value	Location	Current
Regex timeout	keyword_search.py	1.0 second
Max pattern length	keyword_search.py	500 chars
Batch size	keyword_search.py	50 files
Loop nesting threshold	performance_checker.py	2

Proposed Solution

Option A: Environment variables

MCP_REGEX_TIMEOUT=2.0
MCP_MAX_PATTERN_LENGTH=1000

Option B: Configuration file

[workshop_mcp]
regex_timeout = 2.0
max_pattern_length = 1000

Option C: Constructor parameters with defaults

Acceptance Criteria

• All hardcoded values identified
• Configuration mechanism chosen and implemented
• Default values preserved for backward compatibility
• Documentation updated