build(deps): move @intx/* to peers and require arktype ^2.2.3

[TheGreatAxios]

Summary

• @intx/inference and @intx/types move to peerDependencies (^0.4.0) with 0.4.0 devDependency pins; unused @intx/log is dropped.
• arktype requires ^2.2.3, so hosts keep a single copy.
• IMPLEMENTATION.md lists the peers in its dependencies table.
• Base of the stack; merge order build(deps): move @intx/* to peers and require arktype ^2.2.3 #9, refactor!: replace ModelRequestError with EmbeddingRequestError #10, test: use inference-testing fakes and add e2e retry, base64, live suites #11, build: add eslint config and lint script #12, docs: rewrite README quickstart and move dev docs to CONTRIBUTING #13, test: move harness and live tests into e2e/ #14.

Verification

• typecheck, build and bun run test (22 pass); npm pack --dry-run and CI pass.

Closes CL-9063
Closes CL-9066

[TheGreatAxios]

Review

Independent review of the stack found: bad base64 replies escaped as a raw DOMException or silently truncated vectors; non-integer indices were accepted; duplicate-index and non-JSON-200 coverage was lost; the live suite failed instead of skipping when the model was absent. All fixed in this stack (strict base64 decode, number.integer index, restored harness tests, model-aware skip).

Remaining notes: peer range >=0.4.0 follows sibling convention. Each commit typechecks, tests, and builds standalone.