feat: add export_report tool for timeline report generation

Adds export_report MCP tool that generates structured session reports from
timeline data. Supports markdown and HTML output with:

- Activity overview stats (prompts, tool calls, commits, corrections)
- Daily activity sparklines and hourly distribution
- Tool usage breakdown with visual bars
- Weekly summaries with commit logs
- Correction tracking and rate calculation
- Save-to-file support

Closes #5

Author: TerminalGravity

src/index.ts

@@ -49,6 +49,7 @@ import { registerScanSessions } from "./tools/scan-sessions.js";
 import { registerGenerateScorecard } from "./tools/generate-scorecard.js";
 import { registerSearchContracts } from "./tools/search-contracts.js";
 import { registerEstimateCost } from "./tools/estimate-cost.js";
+import { registerExportReport } from "./tools/export-report.js";
 
 // Validate related projects from config
 function validateRelatedProjects(): void {
@@ -110,6 +111,7 @@ const toolRegistry: Array<[string, RegisterFn]> = [
   ["generate_scorecard", registerGenerateScorecard],
   ["estimate_cost", registerEstimateCost],
   ["search_contracts", registerSearchContracts],
+  ["export_report", registerExportReport],
 ];
 
 let registered = 0;