Add a local gameplay analytics dashboard

[darrinm]

Cloudflare's Dashboards section cannot chart gameplay analytics. Its dataset list offers Cloudflare's own telemetry: D1 Analytics, D1 Queries and D1 Storage report rows read, query latency and storage size for astrapool-analytics, and Workers Analytics Engine groups only by dataset name. None of them read rows out of the games table, so they cannot break racks down by mode, difficulty or room.

This adds a dashboard that runs the queries itself.

npm run analytics:dashboard                 # opens http://localhost:8788
npm run analytics:dashboard -- --port 9000 --local --no-open

One page holds the summary tiles, a daily starts chart split into finished, ended early and unfinished, game modes, winners, and all eight settings breakdowns, with buttons for the range (24 hours, 7, 30, 90 days) and the game mode. It serves the same report() output as npm run analytics, so the two always agree.

It listens on 127.0.0.1 only, and each refresh runs the fixed report queries through Wrangler's existing login. No analytics credential is published, stored in the browser, or added to the game, and the public Worker is unchanged.

tools/d1.mjs holds the Wrangler-backed database adapter the CLI already had, so both reports share one code path.

wrangler --json reports API failures as a JSON object on stdout, which neither caller read. A failed report printed Node's Command failed message with the full SQL attached, and said nothing about the cause. Both now print the API's own text, and when the failure is an authorization error while CF_API_TOKEN or CLOUDFLARE_API_TOKEN is set, they name the variable and the command to run without it:

A request to the Cloudflare API (...) failed. The given account is not valid or is not
authorized to access this service [code: 7403] Wrangler is using the API token in
CF_API_TOKEN. Give that token Account / D1 / Read, or run without it:
env -u CF_API_TOKEN npm run analytics:dashboard

Validation: 351 unit tests pass, including eight new ones covering the routes, filter validation, the report shape, query failures and that error message. Production build passes. Checked against the live astrapool-analytics database: the dashboard and npm run analytics -- --mode computer both report 26 started, 21 finished, 80.8% completed. Every table and the chart were checked for clipping and overflow at 360, 480, 800 and 1180 px.

🤖 Generated with Claude Code

https://claude.ai/code/session_01PsSAuUXmXhyA173qE3Y3Fq