[gmatossian]

The JavaScript area currently leads only to Angular references. Add the 12 owner-reviewed JavaScript/RxJS Topics covering browser execution and scheduling, timers and polling, Promise states/chains, async work, and Observable timing/cleanup. Preserve their accepted content and IDs, with the reviewed local diagrams and subject icons.

Closes #132.

The PR includes only this content slice and its hierarchy, icon registry/assets/licenses, focused documentation, and catalog-count expectations. All 12 additions are accepted; the catalog grows from 122 to 134 Topics and keeps its existing 14 drafts. Unrelated pending Java/database/System Design work and editorial rules are excluded.

Verification

• Formatting, lint, tool type checks, 57 app tests, and 153 tooling tests pass.
• Production build passes; the existing nonfatal initial-bundle budget warning remains (793.54 kB).
• 31 Chromium/WebKit/real-catalog browser tests pass in a clean local run. The complete local gate was attempted; Firefox again stalled/timed out at browser startup. Full unmodified CI including Firefox must pass before merge.
• Executed assertions for the reviewed scheduling, Promise/async, concurrency, polling, and RxJS examples; checked all 12 accepted generated entries and 27 reachable source pages.
• Reviewed hierarchy, eight child icons, three loaded diagrams, accepted-status rendering, and representative desktop/390px content containment.

Review and follow-up

AI-assisted packaging, verification, and deliberate review of the complete 43-file diff before push. No independent agent review; Gabriel reviewed and accepted all Topics and explicitly delegated delivery/conditional merge. The 35 added files match that reviewed source material.

#133 tracks phone-width diagram readability; the approved artwork and accessible text remain in this delivery. It is assigned and on the project Backlog.