Merge branch 'claude/project-dependencies': project.cpp dependencies, AGENTS.md

Brings in `#pragma crafter dependency`, the switch to Crafter.LintRules
for the house style, and the contributor guide in AGENTS.md.

The branch predates the musl host work on master, and both rewrote the
command that compiles project.so, so the merge reconciles them by hand:

- LoadProject compiles project.so for hostConfig.target (HostTarget(),
  from master) with the pre-dependency module path and archives from
  the branch. -fuse-ld=lld appears once, with both reasons in the
  comment.
- ForceHostTooling added -fPIC only for the literal x86_64-pc-linux-gnu
  triple. hostConfig now comes from HostTarget(), so on Alpine the host
  is x86_64-alpine-linux-musl and the dependency archive would not have
  been position-independent. It now matches any *-linux-gnu or
  *-linux-musl host, as project.cpp and the cmake flags do since the
  musl change, and its comment no longer argues against HostTarget().
- The ProjectDependency test compared the dependency's target against
  the glibc triple, which the musl CI job would fail; it compares
  against HostTarget().
- README keeps master's paragraph on the bootstrap triple. AGENTS.md
  describes the test block as `if (linuxTarget)`, which is what
  project.cpp has now.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

project.cpp

@@ -3,7 +3,8 @@
 
 import std;
 import Crafter.Build;
-#include "lint-rules.h"
+#pragma crafter dependency "https://forgejo.catcrafts.net/Catcrafts/Crafter.LintRules.git"
+import Crafter.LintRules;
 namespace fs = std::filesystem;
 using namespace Crafter;
 
@@ -142,15 +143,16 @@ extern "C" Configuration CrafterBuildProject(std::span<const std::string_view> a
         // Same LoadProject wiring as ConcurrentCacheRace above.
         cfg.AddTest("HostCacheSourceStamp").Dependencies({ CrafterBuildLib.get() })
             .LinkFlag("-Wl,--export-dynamic").LinkFlag("-ldl");
+        cfg.AddTest("ProjectDependency").Dependencies({ CrafterBuildLib.get() })
+            .LinkFlag("-Wl,--export-dynamic").LinkFlag("-ldl");
         cfg.AddTest("ConcurrentDependencyReset").Dependencies({ CrafterBuildLib.get() });
         cfg.AddTest("Lint").Dependencies({ CrafterBuildLib.get() });
-        cfg.AddTest("HouseRules").Dependencies({ CrafterBuildLib.get() });
     }
 
-    // Dogfood: this repo's house-style rules (see lint-rules.h). Report
-    // rules gate `crafter-build lint`; transform rules also auto-fix under
-    // `crafter-build format`.
-    ProjectLint::AddProjectLintRules(cfg);
+    // Dogfood: the house-style rules, imported from their own repo through
+    // the pragma above. Report rules gate `crafter-build lint`; transform
+    // rules also auto-fix under `crafter-build format`.
+    LintRules::AddRules(cfg);
 
     return cfg;
 }