Add typed completions / sessionConfigCompletions client entry points

[colbylwilliams]

Fixes #340.

Problem

Every client ships the generated Completions* / SessionConfigCompletions* types, but most had no typed way to invoke the completions (session channel) and sessionConfigCompletions (root channel) commands. Callers had to fall back to the untyped request(method: "completions", params: …) with a hand-written method string, losing the compile-time coupling the rest of the client provides.

Cross-client gap analysis

Client	Typed entry point	Before	After
Swift	AHPCommands builder + AHPClient methods	missing both	✅ added builders + convenience methods
Go	Client convenience methods	missing	✅ added Completions / SessionConfigCompletions
Rust	Client convenience methods	missing	✅ added completions / session_config_completions
TypeScript	AhpClient convenience methods	missing	✅ added completions / sessionConfigCompletions
Kotlin	AhpCommands builder (no client layer)	already present	— no change needed

Channel handling

• completions: channel is the caller-set chat URI it is scoped to → preserved (unlike the resource* wrappers).
• sessionConfigCompletions: always targets ahp-root:// → the wrappers force the root channel, matching the resource* family.

Changes

• Swift builders added in scripts/generate-swift.ts, regenerated Messages.generated.swift.
• Hand-written AHPClient / Client / AhpClient convenience methods for Swift, Go, Rust, TypeScript.
• Round-trip tests per client (preserve-channel for completions, force-root for sessionConfigCompletions).
• Per-client changelog fragments under docs/.changes/.

Validation

• Swift swift test — 112 passed
• Go go test ./... — all packages pass (gofmt/go vet clean)
• Rust cargo test -p ahp — all tests + doctests pass (cargo fmt --check clean)
• TypeScript node --test — 65 passed
• npm run lint and npm run verify:change-fragments pass
• npm run generate produces no drift beyond the intended changes

[Copilot]

Pull request overview

Adds first-class, typed client entry points for the completions (session channel) and sessionConfigCompletions (root channel) commands across Swift, Go, Rust, and TypeScript, closing the gap where consumers previously had to use untyped request(method: ...) calls.

Changes:

• Adds typed convenience methods in Swift (AHPClient), Go (Client), Rust (Client), and TypeScript (AhpClient) for completions and sessionConfigCompletions.
• Updates Swift code generation (AHPCommands) and regenerates Messages.generated.swift to include typed request factories for both commands.
• Adds per-client round-trip tests validating channel behavior (preserve caller channel for completions, force root for sessionConfigCompletions) and ships per-client changelog fragments.

Show a summary per file

File	Description
scripts/generate-swift.ts	Extends Swift command-factory generation to include completions + sessionConfigCompletions.
clients/swift/AgentHostProtocol/Sources/AgentHostProtocol/Generated/Messages.generated.swift	Regenerated output adding AHPCommands.completions and AHPCommands.sessionConfigCompletions.
clients/swift/AgentHostProtocol/Sources/AgentHostProtocolClient/AHPClient.swift	Adds typed AHPClient convenience methods for both completions commands (with root-channel forcing for session config).
clients/swift/AgentHostProtocol/Tests/AgentHostProtocolClientTests/AHPClientTests.swift	Adds round-trip tests verifying method names and channel behavior for both wrappers.
clients/typescript/src/client/client.ts	Adds typed AhpClient.completions() and AhpClient.sessionConfigCompletions() wrappers (with root-channel fill-in).
clients/typescript/test/client.test.ts	Adds tests verifying request method names and channel behavior for both wrappers.
clients/rust/crates/ahp/src/client.rs	Adds typed Client::completions() and Client::session_config_completions() wrappers (forcing root channel for session config).
clients/rust/crates/ahp/tests/client_roundtrip.rs	Adds round-trip tests for both Rust wrappers, including channel assertions.
clients/go/ahp/client.go	Adds typed Client.Completions() and Client.SessionConfigCompletions() wrappers (forcing root channel for session config).
clients/go/ahp/client_test.go	Adds round-trip tests for both Go wrappers, including channel assertions.
docs/.changes/20260717-typescript-client-completions.json	Changelog fragment for TypeScript client wrapper additions.
docs/.changes/20260717-swift-client-completions.json	Changelog fragment for Swift client wrapper/builder additions.
docs/.changes/20260717-rust-client-completions.json	Changelog fragment for Rust client wrapper additions.
docs/.changes/20260717-go-client-completions.json	Changelog fragment for Go client wrapper additions.

Review details

• Files reviewed: 13/14 changed files
• Comments generated: 0
• Review effort level: Low

[connor4312]

@copilot resolve the merge conflicts in this pull request

[Copilot]

@copilot resolve the merge conflicts in this pull request

Resolved. The two conflicting files (scripts/generate-swift.ts and Messages.generated.swift) both had the same pattern: this PR added sessionConfigCompletions/completions builders while main added createTerminal/disposeTerminal builders at the same location. The merge keeps all four methods in both files — commit 5a62026.

[connor4312]

@copilot you left merge markers in the code v.v

[Copilot]

@copilot you left merge markers in the code v.v

Removed the remaining conflict markers and restored the missing closing brace for completions in both the generator and generated Swift file. Commit bddc5ed.