chore: rename drift-labs GitHub URLs to velocity-exchange

[ChesterSim]

Part of renaming the GitHub org drift-labs -> velocity-exchange.

DRAFT — do not merge until the velocity-exchange org (and, where applicable, the @velocity-exchange npm scope) exists; old URLs currently redirect.

URL forms changed

• github.com/drift-labs/ -> github.com/velocity-exchange/ (Cargo.toml git deps, Cargo.lock sources, CI workflow dispatch target, CHANGELOG PR links)
• @drift-labs/ npm scope -> @velocity-exchange/ (package.json dep names, TypeScript import statements, yarn.lock entries, eslint rule message, CI workflow yarn-add command)

Total substitutions: 38 across 15 files.

Files changed

File	What changed
.eslintrc.js	eslint rule message referencing @velocity-exchange/sdk
.github/workflows/on-sdk-update.yml	@velocity-exchange/sdk dep lookup, yarn add command, keeper-bots-v2 dispatch URL
CHANGELOG.md	This repo's own PR links (7 links)
Cargo.lock	10 git source URLs for protocol-v2, drift-macros, phoenix-v1, pyth-crosschain
package.json	@velocity-exchange/sdk dev dependency
programs/jit-proxy/Cargo.toml	drift git dep URL
rust/Cargo.lock	3 drift-rs source URLs
rust/Cargo.toml	drift-rs git dep URL
ts/sdk/package.json	Package name @velocity-exchange/jit-proxy, @velocity-exchange/sdk dep
ts/sdk/src/jitProxyClient.ts	2 import statements
ts/sdk/src/jitter/baseJitter.ts	1 import statement
ts/sdk/src/jitter/jitterShotgun.ts	1 import statement
ts/sdk/src/jitter/jitterSniper.ts	1 import statement
ts/sdk/yarn.lock	@velocity-exchange/sdk lock entry
yarn.lock	@velocity-exchange/sdk lock entry

Skipped (upstream-Drift historical refs)

None — no historical/upstream Drift attribution references were found in this repository.

Warning: npm scope breakage

@drift-labs/sdk and @drift-labs/jit-proxy have been renamed to @velocity-exchange/sdk and @velocity-exchange/jit-proxy respectively. Builds will break until these packages are republished under the @velocity-exchange npm scope. The @drift-labs/jit-proxy package name in ts/sdk/package.json has also been updated — downstream consumers that depend on @drift-labs/jit-proxy by name will need to update their own deps once this is published.