Add Sentrix mainnet (7119) to chainIds slug map

[satyakwok]

Adds the chainSlug entry for Sentrix Chain mainnet (chain ID 7119) so the chain card on chainlist.org resolves the icon CDN URL (icons.llamao.fi/icons/chains/rsz_sentrix.jpg) instead of falling back to /unknown-logo.png.

Context:

• The Sentrix Chain entries (chainid-7119.js, chainid-7120.js) were merged via Add Sentrix Chain (mainnet 7119, testnet 7120) #2707.
• Without an entry in constants/chainIds.js, populateChain() leaves chainSlug undefined and components/chain/index.js falls back to the diamond placeholder.

Companion PR:

• DefiLlama/icons (branch v2) — adding assets/chains/rsz_sentrix.png so the CDN actually serves a thumbnail. Linked in the comments below once opened.

Verification (post-merge expected):

• https://icons.llamao.fi/icons/chains/rsz_sentrix.jpg should return 200 image/webp
• chainlist.org chain card for ID 7119 should render the Sentrix mark instead of the Ethereum diamond

Single-line addition, sorted between 7070 (planq) and 7171 (bitrock).

[satyakwok]

Companion icon PR opened: DefiLlama/icons#2374 (against v2 branch). Asset is the same brand mark in PNG; CDN transcodes regardless of source extension.

[satyakwok]

Gentle nudge whenever you have a moment, @Define101 — single-line addition to constants/chainIds.js so the Sentrix Chain card on chainlist.org resolves the icon URL instead of falling back to the unknown-logo diamond. Pairs with the asset PR at DefiLlama/icons#2374 (just nudged @realdealshaman on that one too — its CDN-side complement). Both are 1-click reviews if you have a sec. Thanks!