F7: one-time read-only import of the official kimi-cli configuration

New `kigi import-kimi` (with --dry-run) plus a one-time welcome-screen
hint when ~/.kimi/config.toml is present and unimported.

- Sources: ~/.kimi/config.toml (default_model, [models.*], [providers.*])
  and ~/.kimi/mcp.json ({"mcpServers": ...} — parsed by the existing
  McpConfig machinery). Shapes ported from kimi-cli 1.49.0 config.py with
  citations.
- Strictly read-only over ~/.kimi: plain reads only; the test suite pins
  byte-identical contents AND unchanged mtimes across scan+apply. Keyring
  credentials are never imported; KIMI_SHARE_DIR / any KIMI_* env var is
  never consulted (official dir hardcoded to ~/.kimi).
- Mapping: MCP servers merge into kigi [mcp_servers.*] without clobbering
  existing names; models on non-built-in providers become kigi [model.*]
  custom entries (base_url + api_key + context_window); providers that
  duplicate kigi's built-in Kimi/Moonshot platforms are skipped with a
  note; default_model maps to the imported alias or the managed catalog
  key and never overwrites an existing default.
- One-time marker ~/.kigi/kimi_import_done (claude-import convention);
  the startup hint and re-runs no-op once set. api_key values flow only
  into the user's own config.toml and are redacted in every summary.

Verified end-to-end with the real binary in a sandboxed home: dry-run,
apply, `kigi mcp list` shows both imported servers, second run no-ops,
~/.kimi mtimes unchanged. 8 unit tests + CLI parse test.

crates/codegen/kigi-tui/src/import_kimi_cmd.rs

@@ -0,0 +1,33 @@
+//! `kigi import-kimi` — one-time, read-only import of the official kimi-cli
+//! configuration (`~/.kimi`), PRD F7.
+//!
+//! Reads `~/.kimi/config.toml` + `~/.kimi/mcp.json` without modifying them
+//! and merges MCP servers, custom model providers, and the default-model
+//! preference into `~/.kigi/config.toml`. Existing kigi entries are never
+//! overwritten. A marker file under the kigi home makes the import one-time.
+
+use anyhow::Result;
+
+pub fn run(dry_run: bool) -> Result<()> {
+    if kigi_shell::kimi_import::is_kimi_import_marked() {
+        println!(
+            "kimi-cli settings were already imported (marker: {}).\n\
+             Delete the marker file and re-run to import again.",
+            kigi_shell::kimi_import::kimi_import_marker_path().display()
+        );
+        return Ok(());
+    }
+    let Some(plan) = kigi_shell::kimi_import::scan()? else {
+        println!("Nothing to import: no importable settings found in ~/.kimi.");
+        return Ok(());
+    };
+    print!("{}", plan.summary());
+    if dry_run {
+        println!("\nDry run: nothing was written.");
+        return Ok(());
+    }
+    let applied = kigi_shell::kimi_import::apply(&plan)?;
+    println!();
+    print!("{}", applied.summary());
+    Ok(())
+}