bug(adapters): sanitizeSource does not isolate shared contexts #374

Summary

Unnamed React and Vue hooks with sanitizeSource can reuse the default shared context because private-context detection only checks sanitizeMeta, sanitizeText, textExtractor, and maxHistory.

As a result, source sanitization depends on mount order: the hook may reuse a context created without its sanitizer, or unrelated consumers may unexpectedly share sanitization configuration.

Evidence

• packages/react/src/useAskable.ts, hasContextCreationOptions() omits sanitizeSource.
• packages/vue/src/useAskable.ts has the same omission.
• Solid and Qwik shared-context keys also do not represent all context-creation options.

Proposed fix

• Add sanitizeSource to private-context detection.
• Define consistent adapter semantics for all AskableContextOptions that alter context identity.
• Prefer explicit context identity/key logic rather than ad hoc option checks per framework.

Acceptance criteria

• An unnamed sanitizeSource consumer receives a private sanitized context
• Default and sanitized consumers remain isolated in either mount order
• Named contexts retain explicitly documented sharing behavior
• React, Vue, Solid, and Qwik have parity coverage for context-creation options