docs(street-level): shorten docs and comments before merge

Trim the doc text this PR adds (README, CHANGELOG, CURRENT-STATE,
KNOWN-ISSUES, SECURITY, DATA_SOURCES, .env.example, the CI job comment),
drop code comments that restate the code, cut design-note JSDoc to a line
or two, and drop review tags from test names. Comments only; no code
changes.

Also: README key count (seven keys, two metered), CURRENT-STATE's gate
paragraph (CI runs a production build with a dummy token), the stacked
doc above meshBoxInRange and the orphaned inMeshRange line in
coverage.js, and a duplicate ALPR row in DATA_SOURCES that a merge had
brought back.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/layers/streetLevel/uiState.js

@@ -18,9 +18,8 @@ import { COLORS } from './policy.js';
  */
 
 /**
- * What the switched-on providers add up to: summed counts, any loading, the
- * first hint and error, whether every one of them lacks its key, and whether
- * that is because a provider rejected the key it was given.
+ * Totals over switched-on providers. Key-gated only when every one lacks its
+ * key; `keyRejected` when that is because a key was refused.
  * @param {Array<ProviderSnapshot>} providers
  */
 export function summarizeCoverage(providers) {
@@ -40,12 +39,8 @@ export function summarizeCoverage(providers) {
 }
 
 /**
- * Compose the snapshot the panel renders from the core state and one
- * snapshot per registered provider. Pure, so the merge rules are testable:
- * counts add up across active providers, the layer is key-gated only when
- * every switched-on provider lacks its key, and the legend lists one swatch
- * per active source, in its colour and under its name, followed by the
- * shared selection colour.
+ * The panel snapshot from core state and provider snapshots. The legend has
+ * one swatch per active source, then the shared selection colour.
  * @param {{enabled: boolean, filter: object, providers: Array<ProviderSnapshot>, street: object, sequence: object}} input
  */
 export function composeUIState({