[Docs] Docs still say Stripe is unwired and describe the removed commerce service

[LazyyVenom]

Problem

Several docs still describe the setup from before ADR-0020 and commit f95288d. Some of it would lead an operator to misconfigure a store.

Would mislead an operator

• DEPLOYMENT.md:191 says the Stripe secret key is "not yet consumed — stored, but no live payment path reads it". DEPLOYMENT.md:232 says every deployment is on the OFFLINE path. Both have been wrong since f95288d: packages/plugin/src/payments/stripe-wiring.ts:59-71 builds the live gateway when both the secret key and the webhook secret are set. An operator following the docs could leave out the webhook secret, and then checkout refuses every order (STRIPE_NOT_CONFIGURED).
• DEPLOYMENT.md:282 says Stripe calls go through globalThis.fetch. They now go through ctx.http.fetch (stripe-wiring.ts:47-49).
• ADR-0020 (around line 112) carries the same "Stripe not wired" caveat. Add a dated note rather than editing the decision.

Understates what's built

• README.md:33, :75 and :144 say the storefront covers "catalog + cart only". Checkout, the Stripe pay page and order confirmation exist (sites/staging/src/pages/checkout/*, orders/[orderId].astro), and sites/staging/README.md already says so.

Still describe the removed service

• CLAUDE.md lines 9, 37 and 95 say the plugin "carries the commerce service" and reaches "the service" via ctx.http, and include an "HTTP tasks" check against HttpCommerceClient, which no longer exists.
• DEVELOPMENT.md §2, §3 and §5 have the same service-era wording.
• packages/plugin/README.md:15-22 and :60-70 list HttpCommerceClient, a build-time mode flag, and a test file that no longer exists.
• The packages/plugin/package.json description says "No DB/storage capability".
• The packages/store-emdash/package.json description says a vendored emdash build is required. The workspace uses published emdash@0.38.0 with no overrides (pnpm-workspace.yaml), and build and all test tiers pass on it.
• The packages/store-emdash/README.md:537-541 section points to test/order-contract-b2.ts, which doesn't exist.
• sites/staging/wrangler.jsonc comments point to "DEPLOYMENT.md §3.2", which no longer exists (now §2.1). They also justify global_fetch_strictly_public by the removed Worker-to-service call.
• CLAUDE.md and playwright.config.ts say "18 sandbox suites"; there are 24 (packages/plugin/test/*.sandbox.test.ts).

Proposed fix

One [Docs] PR that corrects the statements above. No code changes.

Validation

• pnpm format:check passes.
• grep -rn "HttpCommerceClient\|not yet consumed\|catalog + cart only" finds nothing outside adr/.

Found in a read-only audit of main @ 3264354.