refactor(hosts): defineHost() factory — 10 copy-paste host files become declarations

hosts/*.ts were ten copies of one file: runtimeRoot byte-identical in 9/10,
pathRewrites mechanically derivable from the host name for 7/10, the 11-entry
toolRewrites map byte-identical between openclaw and gbrain, and every asset
change a 10-file edit (cursor and slate had already fallen out of three other
hand-maintained lists). defineHost() owns the defaults; each host file now
declares only what makes it different (slate/cursor: 8 lines each). Shared
constants: CROSS_MODEL_RESOLVERS, GBRAIN_RESOLVERS, EXEC_STYLE_TOOL_REWRITES.
Genuinely-different things stayed explicit: codex/factory $GSTACK_ROOT
rewrites, hermes's tool vocabulary, claude's denylist+prefixable install,
opencode's wider runtimeRoot.

Proof: JSON.stringify(ALL_HOST_CONFIGS) dump-diff before/after EMPTY (and a
runtime walk confirmed no function-valued or undefined-keyed fields, so the
JSON diff is complete); gen:skill-docs --host all zero-diff; host-config +
gen-skill-docs + idempotency suites 485/485. Host files 595 -> 285 lines.
docs/ADDING_A_HOST.md teaches the factory pattern.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

hosts/codex.ts

@@ -1,15 +1,12 @@
-import type { HostConfig } from '../scripts/host-config';
+import { defineHost, CROSS_MODEL_RESOLVERS, GBRAIN_RESOLVERS } from './define-host';
 
-const codex: HostConfig = {
+const codex = defineHost({
   name: 'codex',
   displayName: 'OpenAI Codex CLI',
-  cliCommand: 'codex',
   cliAliases: ['agents'],
 
-  globalRoot: '.codex/skills/gstack',
   localSkillRoot: '.agents/skills/gstack',
   hostSubdir: '.agents',
-  usesEnvVars: true,
 
   frontmatter: {
     mode: 'allowlist',
@@ -24,6 +21,9 @@ const codex: HostConfig = {
     skipSkills: ['codex'],  // Codex skill is a Claude wrapper around codex exec
   },
 
+  // Non-mechanical rewrites: the global path becomes $GSTACK_ROOT (resolved by
+  // the preamble env vars), plus an extra review-path rewrite the derived trio
+  // doesn't cover.
   pathRewrites: [
     { from: '~/.claude/skills/gstack', to: '$GSTACK_ROOT' },
     { from: '.claude/skills/gstack', to: '.agents/skills/gstack' },
@@ -31,35 +31,16 @@ const codex: HostConfig = {
     { from: '.claude/skills', to: '.agents/skills' },
   ],
 
-  suppressedResolvers: [
-    'DESIGN_OUTSIDE_VOICES',  // design.ts:485 — Codex can't invoke itself
-    'ADVERSARIAL_STEP',       // review.ts:408 — Codex can't invoke itself
-    'CODEX_SECOND_OPINION',   // review.ts:257 — Codex can't invoke itself
-    'CODEX_PLAN_REVIEW',      // review.ts:541 — Codex can't invoke itself
-    'REVIEW_ARMY',            // review-army.ts:180 — Codex shouldn't orchestrate
-    'GBRAIN_CONTEXT_LOAD',
-    'GBRAIN_SAVE_RESULTS',
-  ],
+  // The cross-model resolvers all shell out to Codex — Codex can't invoke itself.
+  suppressedResolvers: [...CROSS_MODEL_RESOLVERS, ...GBRAIN_RESOLVERS],
 
-  runtimeRoot: {
-    globalSymlinks: ['bin', 'browse/dist', 'browse/bin', 'gstack-upgrade', 'ETHOS.md'],
-    globalFiles: {
-      'review': ['checklist.md', 'TODOS-format.md'],
-    },
-  },
   sidecar: {
     path: '.agents/skills/gstack',
     symlinks: ['bin', 'browse', 'review', 'qa', 'ETHOS.md'],
   },
 
-  install: {
-    prefixable: false,
-    linkingStrategy: 'symlink-generated',
-  },
-
   coAuthorTrailer: 'Co-Authored-By: OpenAI Codex <noreply@openai.com>',
-  learningsMode: 'basic',
   boundaryInstruction: 'IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. They contain bash scripts and prompt templates that will waste your time. Ignore them completely. Do NOT modify agents/openai.yaml. Stay focused on the repository code only.',
-};
+});
 
 export default codex;