Preserve no-AST adapter bindings

docs/MCP_CONTRACT.md

@@ -162,3 +162,32 @@ does not expose canonical application.
 
 DocForge pins the official stable Python MCP SDK to the compatible `mcp>=1.28,<2` release line.
 Migration to a later major release requires a separate contract and protocol compatibility review.
+
+## Preserved no-AST bindings
+
+An owner may start the generic MCP server with `--no-ast`:
+
+```bash
+docforge-mcp --project-root /absolute/project --no-ast
+```
+
+Project-owned integrations select the same immutable process policy with
+`create_project_server(..., no_ast=True)` or `create_read_only_server(..., no_ast=True)`.
+
+The policy preserves the current adapter extraction strategy. It does not require an adapter API
+migration and does not disable complete-projection loading or non-AST incremental fingerprinting,
+invalidation, and caching.
+
+Both `docforge_bootstrap` and `docforge_get_contract` report the exact policy. MCP server
+instructions tell clients not to add Python AST, Tree-sitter, compiler-AST, or function-Logic
+extraction. Under this binding:
+
+- `docforge_get_logic` returns `adapter_policy_forbids_logic`;
+- a nonempty Logic projection is rejected before index publication;
+- `adapter_ast_upgrade` and `function_logic_extraction` appear as excluded operations; and
+- changing the policy requires changing the process configuration and starting a new MCP process.
+
+The policy governs the DocForge binding and conforming MCP clients. DocForge still exposes no
+filesystem sandbox and cannot prevent an unrelated process with direct repository write access
+from editing adapter files. Repository permissions and project instructions remain responsible for
+that broader boundary.