refactor: enforce ktx naming and AGENTS.md compliance sweep (#289)

Align the tree with AGENTS.md/CLAUDE.md conventions:

- Rewrite user-facing strings, docs, and tests to lowercase `ktx`
  (no bare uppercase `KTX` tokens remain outside literal identifiers).
- Drop the legacy `historicSql` migration path and its now-unused
  helpers, per the no-backward-compat rule.
- Remove `as unknown as` / `any` casts: narrow `BaseTool` generics to
  `z.ZodObject`, add a typed `createLookerClient`, and delete the dead
  `getParametersSchema`/`toAnthropicFormat` pre-AI-SDK helpers.
- Use `InvalidArgumentError` for Commander parse failures.
- Finish the adapter→connector prose conversion in the `ktx.yaml` docs
  while keeping the literal `adapters` config key.

scripts/build-python-runtime-wheel.mjs

@@ -32,7 +32,7 @@ export function runtimeWheelPyproject() {
   return `[project]
 name = "${RUNTIME_WHEEL_DISTRIBUTION_NAME}"
 version = "${RUNTIME_WHEEL_PACKAGE_VERSION}"
-description = "Bundled Python runtime payload for the KTX npm package"
+description = "Bundled Python runtime payload for the ktx npm package"
 readme = "README.md"
 requires-python = ">=3.13"
 license = "Apache-2.0"
@@ -76,7 +76,7 @@ packages = ["semantic_layer", "ktx_daemon"]
 export function runtimeWheelReadme() {
   return `# kaelio-ktx Python runtime
 
-Bundled Python runtime wheel for KTX.
+Bundled Python runtime wheel for ktx.
 
 This wheel is built from the repository's \`semantic_layer\` and
 \`ktx_daemon\` source trees for inclusion in the npm package. It is not a