Merge refreshed rfc/pty into feature/persistent-pty-sessions

# Conflicts:
#	docs/architecture.md
#	docs/capability-seams.md
#	docs/config-catalog.md
#	docs/cordis-catalog/services.md
#	docs/module-graph.md
#	docs/tool-catalog.md
#	examples/acp-agent/tests/acp.snapshot.ts
#	examples/headless-agent/tests/headless.snapshot.ts
#	examples/package.json
#	packages/README.md
#	packages/cordis/tool-cordis/src/api-catalog.ts
#	packages/core/tools/tests/gen-tool-catalog.spec.ts
#	pnpm-lock.yaml
#	pnpm-workspace.yaml
#	scripts/gen-tool-catalog.ts
#	scripts/type-equiv.manifest.json
#	website/.vitepress/config/api-sidebar.json

docs/architecture.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write
+architecture.md: 1db749ec8b6c6a8872bdc1280cd50dbf0583e159
+architecture.zh.md: 8d05765eb94853076cf8f13c390cef01da07281f