fix(tooling): read a documented call through a property path, so the client namespace tour is graded (#16209)

`check:published-readme-exports` matched exactly one dot between receiver and
member, so `client.ai.chat(…)` matched nothing at all — not the checked half,
and not the `NOT read` half either. `packages/client`'s namespace tour, the npm
front page of `@objectstack/client`, contributed three unread sites, all of them
`console.log`/`console.error`/`Math.pow`, and none of its ~30 documented calls.

The matcher now carries the property path between receiver and member, and
`memberAtPath` walks it from a receiver type the gate already resolves, naming
the segment that fails rather than the member at the end. Both halves became
filters over one walk (`memberCallSites`), so the split the green line prints
cannot stop being a split.

Measured on this tree: call-site half 78 -> 120, `NOT read` 122 -> 133. The pair
RISES by the 11 chained sites on untyped roots that were previously invisible to
both halves; nothing about what the bucket reports is narrowed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012GKcPZbMoGq7WPzKLfRBTU

Author: claude