feat(cli): crafter-debug, the client agents drive an app with

Cli::Run is the whole client but its transport, so tests run it in
process against a real Session; main will hand it the QUIC connection.

- Commands: ls, status, cmds, help, call, get, set, pause, resume,
  step, wait, trace, log (with --follow), screenshot, quit, debugger,
  guide and version, with -i, --json and --timeout.
- call types key=value from the command's argument schema (slot=1 is
  a number, name=1 a string, at.x=3 nests), so agents need no JSON
  for simple calls; a value that cannot fit its field is a usage
  error before anything is sent.
- The instance comes from discovery; one running instance needs no -i.
  The record's protocol is checked before any request: a mismatch
  exits 4, says which side is newer and prints the app's own client.
  Other sources only warn.
- A request with no reply is diagnosed: the app has exited, stopped
  in a debugger (with the attach command), or no longer calls Pump
  (with what to change). Exit codes: 2 usage, 3 no instance,
  4 version, 5 timeout, 6 the app's error.
- Output is short by default, arrays cut at 20 with a note; --json
  prints everything. `guide` is the full reference for agents.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

project.cpp

@@ -1,11 +1,13 @@
 // SPDX-License-Identifier: LGPL-3.0-only
 // SPDX-FileCopyrightText: Copyright (C) 2026 Catcrafts®
 
-// Three configurations:
+// Four configurations:
 //   Crafter.Debug.Core  what the app and the client share (values, codecs,
 //                       the protocol, discovery, build info)
+//   Crafter.Debug.Cli   the client's code, a library so tests can run it
 //   crafter.debug-cli   the client, crafter-debug
-//   Crafter.Debug       what an app links (returned), depending on both
+//   Crafter.Debug       what an app links (returned), depending on the core
+//                       and the client
 // The client is one of the library's dependencies only so that a consumer's
 // debug build compiles it in the same pass as the app; an executable adds no
 // link flags to what depends on it. Consumers load this file through
@@ -135,7 +137,20 @@ extern "C" Configuration CrafterBuildProject(std::span<const std::string_view> a
     client.mtune = cfg.mtune;
     client.sysroot = cfg.sysroot;
     client.debug = cfg.debug;
-    client.dependencies = { &core };
+
+    // The client's code as a library, so tests can run it in process.
+    Configuration& cli = owned.emplace_back();
+    cli.path = Root();
+    cli.name = "Crafter.Debug.Cli";
+    cli.outputName = "Crafter.Debug.Cli";
+    cli.type = ConfigurationType::LibraryStatic;
+    cli.target = cfg.target;
+    cli.march = cfg.march;
+    cli.mtune = cfg.mtune;
+    cli.sysroot = cfg.sysroot;
+    cli.debug = cfg.debug;
+    cli.dependencies = { &core };
+    client.dependencies = { &cli };
 
     {
         std::array<fs::path, 8> interfaces = {
@@ -157,6 +172,11 @@ extern "C" Configuration CrafterBuildProject(std::span<const std::string_view> a
         };
         core.GetInterfacesAndImplementations(interfaces, implementations);
     }
+    {
+        std::array<fs::path, 2> interfaces = { "interfaces/Crafter.Debug.Cli-Client", "interfaces/Crafter.Debug.Cli" };
+        std::array<fs::path, 1> implementations = { "implementations/Crafter.Debug.Cli-Client" };
+        cli.GetInterfacesAndImplementations(interfaces, implementations);
+    }
     {
         std::array<fs::path, 0> interfaces = {};
         std::array<fs::path, 1> implementations = { "implementations/main" };
@@ -186,6 +206,7 @@ extern "C" Configuration CrafterBuildProject(std::span<const std::string_view> a
     if (IsTopLevelProject()) {
         for (const std::string_view test : coreTests) cfg.AddTest(test).Dependencies({ &core });
         for (const std::string_view test : libraryTests) cfg.AddTest(test).Dependencies({ &cfg });
+        cfg.AddTest("ShouldRunClientCommands").Dependencies({ &cfg, &cli });
     }
     return cfg;
 }