test(functionalities): fix copy-page button test hydration race

[g-despot]

The nightly Docs Functionalities Tests suite has been red (both test_copy_page_button_writes_markdown params: /weaviate/quickstart, /weaviate/search/bm25) since at least Jul 5 — the "Copy page" button never showed "Copied!" within the timeout.

Root cause: a hydration race in the test — not a feature bug, not clipboard

The button is server-rendered, so Playwright reports it "visible" before React hydrates and attaches its onClick. A click landing in that gap is silently dropped, so the label stays on "Copy page" and never reports success. The fixture already grants clipboard-read/clipboard-write, and a direct Clipboard API round-trip works in the test context — clipboard was a red herring. It fails deterministically (not flaky) because heavier pages and slower headless CI runners lose the race every time. The copy-page feature itself (from #460) is deployed and works.

Fix (test-only)

After the button is visible, wait for the page JS to finish loading (wait_for_load_state("networkidle"), non-fatal so a chatty live page can't hang the test), then retry the click a few times until the aria-live span reports "Copied!". No site source changed.

Verification

uv run pytest -m functionalities against live docs.weaviate.io:

• test_copy_page_button_writes_markdown[/weaviate/quickstart] — PASSED
• test_copy_page_button_writes_markdown[/weaviate/search/bm25] — PASSED

Stable across repeated runs (verified independently). All downstream assertions (markdown length, Source: prefix, fenced code block, no page chrome) still pass.

[orca-security-eu]

Orca Security Scan Summary

Status	Check	Issues by priority
Passed	Infrastructure as Code	0   0   0   0	View in Orca
Passed	SAST	0   0   0   0	View in Orca
Passed	Secrets	0   0   0   0	View in Orca
Passed	Vulnerabilities	0   0   0   0	View in Orca