feat(cli): smart defaults and flatter command surface for ktx (#177)

Bare invocations now do the obvious thing instead of erroring out, and mode-as-subcommand patterns collapse into flags on the parent. No new top-level commands.

- `ktx ingest` (bare) ingests every configured connection. The `text` subcommand is gone; capture inline notes with `ktx ingest --text "..."` and files with `ktx ingest --file path` (use `-` for stdin). `--text`/`--file` reject a positional connection id; pass `--connection-id` to tag captured notes.
- `ktx connection` (bare) lists; `ktx connection test` (bare) tests every configured connection.
- `ktx wiki` and `ktx sl` flatten `list`/`search`: bare lists, with a `[query...]` positional searches (multi-word joined with spaces). `sl validate` and `sl query` stay as distinct verbs and now read `--connection-id` from the parent.
- `ktx mcp` (bare) prints daemon status.

Adds a shared `resolveConnectionSelection` helper consumed by ingest and connection test. Updates README, docs-site cli-reference and guides, next-steps strings, agent SKILL templates, and all affected tests. Per-package type-check, unit tests (605), smoke tests, and dead-code checks all pass.

packages/cli/src/next-steps.ts

@@ -1,7 +1,7 @@
 export const KTX_CONTEXT_BUILD_COMMANDS = [
   {
-    command: 'ktx ingest --all',
-    description: 'Build or refresh agent-ready context from configured connections',
+    command: 'ktx ingest',
+    description: 'Build or refresh agent-ready context from all configured connections',
   },
   {
     command: 'ktx status',
@@ -15,11 +15,11 @@ export const KTX_NEXT_STEP_DIRECT_COMMANDS = [
     description: 'Verify project setup and context readiness',
   },
   {
-    command: 'ktx sl list',
+    command: 'ktx sl',
     description: 'Inspect generated semantic-layer sources',
   },
   {
-    command: 'ktx wiki list',
+    command: 'ktx wiki',
     description: 'Inspect generated wiki pages',
   },
 ] as const;