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.

packages/cli/src/context/project/project.ts

@@ -123,7 +123,7 @@ export async function initKtxProject(options: InitKtxProjectOptions): Promise<In
 
   const commit = await runtime.git.commitFiles(
     ['ktx.yaml', ...TRACKED_SCAFFOLD_FILES.map((file) => file.path)],
-    `Initialize KTX project: ${projectName}`,
+    `Initialize ktx project: ${projectName}`,
     authorName,
     authorEmail,
   );