Integrations — landing page (evm/integrations/index)

**Page:** `evm/integrations/index.mdx`

**Context:** Subdirs `cross-chain/` (chainlink-ccip, layerzero), `oracles/` (chainlink, pyth, supra), `indexing/`, `wallets/` — most leaf pages written.

**Scope:** Overview routing into oracles / cross-chain / indexing / wallets.

### Acceptance criteria
- [ ] Replace the placeholder template with a real landing page
- [ ] Remove `hidden: true` from the frontmatter
- [ ] **No "Browse by section" block** — the side nav covers that; open straight into the deep-dive sections
- [ ] Route into the written sibling pages via ``/``
- [ ] Follow the style guide (markdown tables only; no AI-tell phrasing)