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/setup-agents.ts

@@ -569,8 +569,8 @@ function cliInstructionContent(input: { projectDir: string; launcher: KtxCliLaun
     'Available commands:',
     '',
     `- \`${ktxCommandLine(input.launcher, ['status', ...jsonProjectDirArgs])}\``,
-    `- \`${ktxCommandLine(input.launcher, ['sl', 'list', ...jsonProjectDirArgs])}\``,
-    `- \`${ktxCommandLine(input.launcher, ['sl', 'search', '<text>', ...jsonProjectDirArgs, '--connection-id', '<id>'])}\``,
+    `- \`${ktxCommandLine(input.launcher, ['sl', ...jsonProjectDirArgs])}\``,
+    `- \`${ktxCommandLine(input.launcher, ['sl', '<text>', ...jsonProjectDirArgs, '--connection-id', '<id>'])}\``,
     `- \`${ktxCommandLine(input.launcher, [
       'sl',
       'query',
@@ -585,7 +585,7 @@ function cliInstructionContent(input: { projectDir: string; launcher: KtxCliLaun
       '--max-rows',
       '100',
     ])}\``,
-    `- \`${ktxCommandLine(input.launcher, ['wiki', 'search', '<query>', ...jsonProjectDirArgs, '--limit', '10'])}\``,
+    `- \`${ktxCommandLine(input.launcher, ['wiki', '<query>', ...jsonProjectDirArgs, '--limit', '10'])}\``,
     '',
     'Use semantic-layer queries before direct database access. Do not print secrets or credential references.',
     '',