[jamie950315]

Problem

The native gateway restores a flattened upstream call such as
collaboration-optimize__wait_agent to collaboration__wait_agent, without a
namespace. Codex declares this tool as namespace: "collaboration" and
name: "wait_agent", so the restored call is rejected with:

unsupported call: collaboration__wait_agent

This breaks multi-agent coordination when an upstream provider returns the
flattened wire form. A chained CPA can also perform its own restoration first,
returning collaboration__wait_agent to Cockpit; that form needs the same
canonical identity when the original request declared the namespaced tool. The same restoration code is present in v1.3.73 and the
current main branch.

Changes

• Restore the double-underscore wire form to a separate namespace and tool name,
  matching the existing dotted-name restoration.
• Require a nonempty tool-name suffix.
• Recover already-restored collaboration__tool calls from a chained CPA only
  when this request declared that collaboration tool and no explicit flat-name
  declaration conflicts. Unknown tools and other namespaces remain unchanged.
• Update the completed-response regression assertion and cover flattened
  spawn/message/followup/wait calls in SSE item-added and item-done events.
• Reuse the existing isolated official Codex CLI lifecycle fixture for both
  canonical and flattened upstream calls. Keep request-context gating, call IDs,
  arguments, input, and tool-result payloads intact.

Validation

Before the fix, the new restoration assertions fail and the flattened CLI
fixture reproduces unsupported call: collaboration__wait_agent.
After the fix:

• 26 multi-agent compatibility tests pass, including the chained-CPA case,
  undeclared names, conflicting flat declarations, namespace isolation, and
  opaque payload preservation.
• Both JSON/SSE/WebSocket lifecycle tests pass.
• Canonical and optimized-flat official Codex CLI lifecycle cases passed.
• An additional official CLI lifecycle case now passes with the chained CPA
  returning collaboration__tool. The parent reaches PARENT_DONE after actual
  child-runtime creation and continuation without an unsupported-call error.

The CLI cases use an installed official CLI with temporary homes/workspaces and
a scripted loopback provider under the existing macOS network sandbox; they do
not use live model inference or account credentials.

cargo test --manifest-path src-tauri/Cargo.toml --lib multi_agent_compat::tests -- --test-threads=1
cargo test --manifest-path src-tauri/Cargo.toml --lib multi_agent_lifecycle -- --test-threads=1
COCKPIT_PLAN_CODEX_BIN=/path/to/official/codex cargo test --manifest-path src-tauri/Cargo.toml --lib multi_agent_lifecycle_real_codex_cli_ -- --ignored --test-threads=1

cargo fmt --package cockpit-tools -- --check reports repository-wide formatting
differences, including untouched files. This PR keeps unrelated formatting out
of the patch.