refactor(constants): create ttl_constants.py — replace raw TTL/timeout integers (#3529)

[mrveiss]

Summary

Creates autobot-backend/constants/ttl_constants.py and replaces 60+ raw integer TTL/timeout literals across 22 files with named constants.

New file: constants/ttl_constants.py

TTL_1_HOUR    = 3_600
TTL_24_HOURS  = 86_400
TTL_7_DAYS    = 86_400 * 7
TTL_30_DAYS   = 86_400 * 30
TTL_90_DAYS   = 86_400 * 90

TIMEOUT_HTTP_DEFAULT  = 60
TIMEOUT_HTTP_LONG     = 120
TIMEOUT_TASK_ANALYSIS = 1_800

Files updated (22 files, 60+ replacements)

86400 (24-hour) Redis TTLs replaced in:
project_state_tracking/tracking.py (×5), prompt_manager.py, agents/npu_code_search_agent.py (×3), user_management/services/session_service.py, services/command_execution_queue.py (×3), chat_history/file_io.py, chat_history_manager.py

3600 (1-hour) Redis TTLs replaced in:
secure_sandbox_executor.py (×2), code_analysis/src/code_analyzer.py (×3), code_analysis/src/api_consistency_analyzer.py, code_analysis/src/ownership_analyzer.py, code_analysis/src/performance_analyzer.py, services/agent_terminal/session_manager.py

Multi-day computed expressions replaced in:
api/analytics_llm_patterns.py (×3), api/analytics_embedding_patterns.py (×3), services/llm_cost_tracker.py (×3), utils/monitoring_alerts.py, code_analysis/src/code_quality_dashboard.py

HTTP/async timeouts replaced in:
chat_workflow/manager.py, llm_interface_pkg/mock_providers.py, api/codebase_analytics/endpoints/report.py (×2), api/codebase_analytics/endpoints/pattern_analysis.py (×3)

Closes #3529

[github-actions]

✅ SSOT Configuration Compliance: Passing

🎉 No hardcoded values detected that have SSOT config equivalents!