feat(#1035): phase 5a — author 16 role:runtime capability descriptors (registry-only) (#1039)

Author capabilities/<runtime>/capability.json for all 16 runtimes (role:runtime),
populating the registry's runtimes index ({} -> 16). Each carries the 6 ADR-1016
axes (configHome structured, configFormat, artifactLayout structured, commandStyle,
hooksSurface + hookEvents, sandboxTier, supportTier), extracted from the live
modules (runtime-homes/runtime-slash/runtime-artifact-layout/runtime-config-adapter
+ CODEX_AGENT_SANDBOX). validateRuntimeBody tightened to enforce the closed
vocabularies + structured configHome/artifactLayout (rejects old string configHome;
env required; skillsHome recursively validated).

Registry-only: bin/install.js + src/*.cts untouched, zero behavior change. The 5b-5f
drive steps consume these one axis at a time (ADR-1016 §8).

Codex accuracy review caught + fixed: opencode/kilo register ZERO lifecycle hooks
(install.js skips the whole block) -> hooksSurface:none (configFormat stays
settings-json); kimi probe selects on <root>/skills existence -> probeExists:"skills".
ArtifactKind required-field strictness + ConverterName closing deferred to 5d/5e.
ADR-1016 (Proposed) amended to match (Decisions 1 + 5).

Closes #1035

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

capabilities/qwen/capability.json

@@ -0,0 +1,34 @@
+{
+  "id": "qwen",
+  "role": "runtime",
+  "title": "Qwen Code",
+  "description": "Qwen Code (Alibaba) — nested-skill artifact layout; settings-json hook surface; Claude hook event dialect; tier-2 support.",
+  "tier": "core",
+  "requires": [],
+  "runtime": {
+    "configHome": {
+      "kind": "dot-home",
+      "name": ".qwen",
+      "env": ["QWEN_CONFIG_DIR"]
+    },
+    "configFormat": "settings-json",
+    "artifactLayout": {
+      "global": [
+        {
+          "kind": "skills",
+          "destSubpath": "skills",
+          "prefix": "gsd-",
+          "nesting": "nested",
+          "recursive": false,
+          "converter": "convertClaudeCommandToClaudeSkill"
+        }
+      ],
+      "local": []
+    },
+    "commandStyle": "slash-hyphen",
+    "hooksSurface": "settings-json",
+    "hookEvents": "claude",
+    "sandboxTier": "none",
+    "supportTier": 2
+  }
+}