feat: Implement skill to add evm networks on extension repo

domains/swaps/skills/add-evm-network/repos/metamask-extension.md

@@ -0,0 +1,24 @@
+---
+repo: metamask-extension
+parent: add-evm-network
+---
+
+# Add EVM Swaps/Bridge Network
+
+`docs/add-evm-swaps-bridge-network.md` is the single source of truth.
+
+## How to use
+
+1. Read `docs/add-evm-swaps-bridge-network.md` in full before editing.
+2. Follow its `Agent Execution Standard (SSOT)` workflow exactly.
+3. Return the `Required Agent Response Sections` listed at the end of that doc.
+
+## Layers at a glance (details in the doc)
+
+- Upstream hard allowlist: `@metamask/bridge-controller` → `ALLOWED_BRIDGE_CHAIN_IDS`.
+- Extension constants: `shared/constants/bridge.ts` → `ALLOWED_EVM_BRIDGE_CHAIN_IDS`, `NETWORK_TO_SHORT_NETWORK_NAME_MAP`, `BRIDGE_CHAINID_COMMON_TOKEN_PAIR`.
+- Stablecoins: `ui/pages/bridge/utils/stablecoins.ts` → `STABLECOIN_ASSET_IDS`.
+- Remote feature flag: `bridgeConfigV2` → `chains`, `chainRanking`, top-level `stablecoins`.
+- Tests: `ui/ducks/bridge/selectors.test.ts`, `ui/hooks/bridge/useSmartSlippage.test.ts`.
+
+Prerequisite: the chain must already exist in `shared/constants/network.ts` and in the installed `@metamask/bridge-controller` hard allowlist. If either is missing, stop and report the blocker.

domains/swaps/skills/add-evm-network-mobile/repos/metamask-mobile.md → domains/swaps/skills/add-evm-network/repos/metamask-mobile.md

@@ -1,6 +1,6 @@
 ---
 repo: metamask-mobile
-parent: add-evm-network-mobile
+parent: add-evm-network
 ---
 
 # Add an EVM Network to Mobile Swaps and Bridge

domains/swaps/skills/add-evm-network/skill.md

@@ -0,0 +1,12 @@
+---
+name: add-evm-network
+description: >-
+  Add a new EVM network to the unified Swaps/Bridge flow in MetaMask
+  Extension or MetaMask Mobile. Use when a task asks to register a new EVM
+  chain for swaps or bridge, consume a newly supported bridge-controller
+  chain, extend the bridge chain allowlist (ALLOWED_EVM_BRIDGE_CHAIN_IDS /
+  ALLOWED_BRIDGE_CHAIN_IDS), add a network label or default destination
+  token, configure stablecoin slippage, or update bridgeConfigV2
+  chains/chainRanking rollout requirements for a new EVM chain. Follow the
+  sibling "add Robinhood/MegaETH chain" pattern.
+---