perf improvements + /login fix

PERFORMANCE.md

@@ -0,0 +1,61 @@
+# Performance Workflow
+
+This repository includes a lightweight performance workflow built around the
+existing startup and query profilers.
+
+## Build Once
+
+```bash
+bun run build
+```
+
+## Baseline Scenarios
+
+1. Cold start and command latency
+
+```bash
+bun run perf:startup -- --help
+```
+
+2. Interactive startup in a real session
+
+```bash
+bun run perf:startup --
+```
+
+Use your OS task manager while the app is idle to inspect CPU, RSS, and handle
+count after first render.
+
+3. Headless query / TTFT
+
+```bash
+bun run perf:query -- --print "Summarize the current directory."
+```
+
+This requires whatever auth/config is normally needed for the chosen provider.
+
+## Artifacts
+
+Each run writes an isolated artifact bundle under `.perf-artifacts/`:
+
+- `summary.json`: wall-clock timing and parsed profiler highlights
+- `config/startup-perf/*`: startup profiler output
+- `config/query-perf/*`: query profiler output
+- `debug/*`: debug logs for runs that need them
+
+## Regression Checks
+
+Run the focused regression checks for the new performance helpers with:
+
+```bash
+bun run perf:regression
+```
+
+## Suggested Before/After Loop
+
+1. Run the startup baseline.
+2. Run the headless query baseline.
+3. If you are changing long-running behavior, also launch an interactive session and
+   watch idle CPU and memory for a few minutes.
+4. Compare the new `.perf-artifacts` summary against the previous run before and
+   after each optimization pass.