docs: fix stale observe*-era internal docs (cuped-private flame-internal CLAUDE.md) + example version label

[madmikeross]

What to build

Two stale docs still describe the removed observe* era: (1) ~/cuped/cuped-private/flame-internal/CLAUDE.md documents flame.observe/observeConversion/observePageview and POST /:apiKey/observations — the live API is track()/useTrack() and POST /{api_key}/events. cuped-private has no tracker, so this issue is homed here. (2) examples/script-tag/index.html self-labels "flame v0.2.0" while the released SDK is 0.5.0. Owed since the 07-05 audit's "doc corrections" list.

Acceptance criteria

• flame-internal CLAUDE.md rewritten for the events-era API (track, /events, current package layout)
• Script-tag example version label corrected (or made version-agnostic)
• Quick grep for any other observe*/observations stragglers across flame + cuped-private docs

Blocked by

None - can start immediately

Source: ember/docs/PLATFORM_AUDIT_2026-07-14.md §1 correction 3 + §4 P2.