feat(harness): port CLI skeleton + nsp phase meta --json (F2, kills JS/Python drift)

nsp.cli app registers phase_app (the gate's workflow-fact source). phase meta
--json emits {schema_version, max_phase, phases:[{num,id,name,advance,artifacts_out}]}
from load_workflow() -- the single source of truth. F8/datamart is present (the
exact JS-drift bug in ChironeWp3, PHASE_NAMES truncated to 7, is structurally gone).

Scope: the 12 other command groups land in their porting tasks (A9 ports
db/mschema/_guards; B1 vectorstore; B3 search/lshindex). Eager-importing them now
would break the app on unported deps -- deferred to keep the suite green at each commit.

harness/nsp/cli/__init__.py

@@ -0,0 +1,41 @@
+"""nsp CLI -- Typer app `nsp`.
+
+Minimal skeleton for now: registers `phase_app` (the gate needs `nsp phase meta --json`).
+Other command groups (db, schema, lsh, vector, memory, session, decision, sql, cte,
+evidence, search) are wired in their porting tasks, once their backend deps land
+(A9 ports db/mschema/_guards; B1 ports vectorstore; B3 ports search/lshindex/sampling).
+"""
+from __future__ import annotations
+
+import typer
+
+from nsp import __version__
+
+app = typer.Typer(
+    help="nsp (Natural Semantic Platform) -- kit operativo per generazione SQL assistita da Pi",
+    no_args_is_help=True,
+)
+
+
+def _version_callback(value: bool) -> None:
+    if value:
+        typer.echo(__version__)
+        raise typer.Exit()
+
+
+@app.callback()
+def main(
+    version: bool = typer.Option(
+        False,
+        "--version",
+        callback=_version_callback,
+        is_eager=True,
+        help="Mostra la versione ed esce.",
+    ),
+) -> None:
+    pass
+
+
+from nsp.cli.phase_cmd import phase_app  # noqa: E402
+
+app.add_typer(phase_app, name="phase")