Proxy, HTTPS, and full test coverage

[pillsilly]

Summary

• New PROXY_STATIC_FILE_WISE mode — serve static files first, proxy all other requests to --proxyTarget. Supports WebSocket upgrade (for HMR/dev servers), strips proxy-fingerprint headers (x-forwarded-*, via), rewrites origin/referer to match the target, and auto-rewrites upstream redirect Location headers to the proxy origin.
• HTTPS support — --https, --httpsKey, --httpsCert CLI flags. Falls back to bundled server.key/server.cert when no custom path given. HTTPS server shares the same routing as HTTP.
• New CLI flags: --proxyStaticFileWise, --https, --httpsKey, --httpsCert
• Refactored run.ts — split monolithic run() into createLegacyServer, createProxyStaticFirstServer, createHttpOrHttpsServer, normalizeProxyRequest, rewriteReferer, resolveHttpsPath, parsePort, validateArguments. Uses http-proxy-middleware v3 API directly (was lazy-required before).
• TypeScript fixes — widen mode literal type to Mode union, drop removed logLevel option, cast Duplex to net.Socket for proxy upgrade.
• Refactored bin.ts — extracted main() and runIfMain() for clean error handling and testability. run errors now log to stderr and exit with code 1 instead of crashing.
• Fixed src/run-https.ts — use path.resolve(__dirname, ...) for cert/key paths so the binary can find them when packaged.
• 100% test coverage — 27 tests (up from 14), covering SPA mode, proxy-static-first with WebSocket, HTTPS, header normalization, redirect rewriting, argument validation, error paths, and uncaughtException handling.

Files changed

File	Δ
src/run.ts	+279/-61
test/test.spec.ts	+668/-78
README.md	+221/-61
test/bin.spec.ts	+150/-8
src/bin.ts	+43/-15
src/run-https.ts	+4/-2
package.json	+3/-1

Test plan

• npm test — 27 tests pass, 100% branch/function/line/statement coverage
• npx tsc -p tsconfig.json --emitDeclarationOnly — zero errors