feat: limit checkout indexing to entrances and expose bounded typed discovery

Content directories always have no indexable children; direct authorized paths remain resolvable. Add List using provider Read/enumeration authority and separate List permission, dirs-first lexical live continuation, bounded retention/path bytes, scoped result coordinates and External DTO validation. List/Glob/Grep return Descriptor-typed entries without eager acquisition. Bind content Interfaces coherently to the live entrance scope.

Validation: root cargo check; FS 58 unit+6 pagination, Workdir 125+5 (default and http-client), Tools 84 unit+39 integration+1 doctest, Worker 901 unit+110 integration, Server 691 unit+11 CLI, Server API 83 tests; exact crates.io WIP 0.2.0 resolution; format/diff checks. Focused model/local/remote/provider/race/scope checks passed. Commands and semantics in docs/development/wip-integration-validation.md.

Publication/review paused: continuation ShowTicket returned HTTP 401. No Backend bypass, source push, MR approval, target integration or live environment update is claimed.

crates/workspace-server/src/server.rs

@@ -54114,6 +54114,7 @@ mod tests {
             WorkdirSessionOperation::List(workdir::ListRequest {
                 path: workdir::WorkdirPath::root(),
                 limit: 10,
+                after: None,
             }),
         )
         .await