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.

python/ktx-daemon/README.md

@@ -1,6 +1,6 @@
 # ktx-daemon
 
-`ktx-daemon` is the portable Python compute package for KTX.
+`ktx-daemon` is the portable Python compute package for **ktx**.
 
 It supports portable compute in two modes:
 
@@ -99,6 +99,6 @@ Code execution is off by default. When enabled, it runs Python `exec` in the
 daemon process with the same in-process boundary as the one-shot
 `code-execute` command and does not provide OS-level sandboxing.
 
-HTTP code execution uses the standalone KTX boundary. It does not forward
+HTTP code execution uses the standalone **ktx** boundary. It does not forward
 caller authorization headers to a host app and does not connect scratchpad or
 visualization helpers to host application APIs.