Visitors, users and page speed are a /boards source #2787

This adds a reach source to src/boards/sources.ts that covers visitors, active accounts, and page and server speed. It is admin-only, so a signed-in non-admin gets 403 and a signed-out request gets 401. The boards tests pass and tsc reported nothing beyond a tempdir warning. I didn't run the full suite, since the forge's check does that on push.

The source is a fixed read-only SQL view over page_vital and session, with rows of metric, route, at and value. You pick a metric with a filter on metric:

• visitors: distinct browsers per day.
• lcp_p75, inp_p75: nearest-rank p75 in ms, per route per day.
• server_p50, server_p95: the same, per route per day, taken from time to first byte.
• accounts_active_1d, accounts_active_7d, accounts_total: counts as of now.

Visitor hashes and user ids are not exposed.

• Server timing: the forge records no per-route server latency anywhere else, so server_p50 and server_p95 use the beacon's time to first byte, which includes network time.
• Account history: the account counts are as of now, because sessions keep only their last-seen time.
• Percentile queries: percentiles are computed per route per day. Taking a max or avg across several days summarises daily percentiles, not a percentile of the whole period. I didn't add percentile aggregates to the query engine.
• Starting board: I didn't add one for this source.

The new test in test/boards-query.test.ts seeds vitals and sessions and checks the exact p75, p50, p95, visitor and account numbers. It also checks that a non-admin is refused (403) and that a signed-out request is rejected (401). reach was also added to the existing admin-only and no-secret-column checks. The README documents the source, and no dependency was added.

To try it, sign in as an admin and query {"source":"reach","aggregate":"max","column":"value","filter":[{"column":"metric","op":"eq","value":"lcp_p75"}],"groupBy":"route"} at /boards/data or POST /api/v1/boards/query.

Closes #2712

This adds a reach source to src/boards/sources.ts that covers visitors, active accounts, and page and server speed. It is admin-only, so a signed-in non-admin gets 403 and a signed-out request gets 401. The boards tests pass and tsc reported nothing beyond a tempdir warning. I didn't run the full suite, since the forge's check does that on push.

The source is a fixed read-only SQL view over page_vital and session, with rows of metric, route, at and value. You pick a metric with a filter on metric:

• visitors: distinct browsers per day.
• lcp_p75, inp_p75: nearest-rank p75 in ms, per route per day.
• server_p50, server_p95: the same, per route per day, taken from time to first byte.
• accounts_active_1d, accounts_active_7d, accounts_total: counts as of now.

Visitor hashes and user ids are not exposed.

• Server timing: the forge records no per-route server latency anywhere else, so server_p50 and server_p95 use the beacon's time to first byte, which includes network time.
• Account history: the account counts are as of now, because sessions keep only their last-seen time.
• Percentile queries: percentiles are computed per route per day. Taking a max or avg across several days summarises daily percentiles, not a percentile of the whole period. I didn't add percentile aggregates to the query engine.
• Starting board: I didn't add one for this source.

The new test in test/boards-query.test.ts seeds vitals and sessions and checks the exact p75, p50, p95, visitor and account numbers. It also checks that a non-admin is refused (403) and that a signed-out request is rejected (401). reach was also added to the existing admin-only and no-secret-column checks. The README documents the source, and no dependency was added.

To try it, sign in as an admin and query {"source":"reach","aggregate":"max","column":"value","filter":[{"column":"metric","op":"eq","value":"lcp_p75"}],"groupBy":"route"} at /boards/data or POST /api/v1/boards/query.

The full gate on land was red and named no test; the pull is open again.