feat(chat-cli): wire up logos-delivery transport and switch to client API

[osmaczko]

Replace the direct use of conversations::Context with client::ChatClient,
which is the intended public API for library consumers.

Remove MessageEnvelope and the username-keyed session model. The envelope
was never part of the wire protocol — sender identity was only tracked in the
CLI's local state. Chats are now keyed by conversation ID; add /nickname as
the user-facing replacement for named sessions.

Add a logos-delivery (Waku) transport alongside the existing file transport.
The active transport is selected at compile time: set LOGOS_DELIVERY_LIB_DIR
to link liblogosdelivery, otherwise the file transport is used.

Add logos-delivery as a Nix flake input and expose .#logos-delivery so the
library can be built with nix build and referenced by LOGOS_DELIVERY_LIB_DIR.

CI: rename c-ffi-smoketest to smoketest; add logos-delivery build step
and a --smoketest invocation of chat-cli to verify startup.

[Copilot]

Pull request overview

Adds a new chat-cli workspace crate that serves as an end-to-end example application for libchat, using logos-delivery (Waku-based) as the transport and ratatui/crossterm for a terminal UI.

Changes:

• Introduces a chat-cli binary with a synchronous TUI event loop for sending/receiving messages.
• Implements a DeliveryService backed by an embedded logos-delivery node via FFI + a background thread.
• Adds build/docs tooling (Makefile targets, build.rs linking via LOGOS_DELIVERY_LIB_DIR, README updates) and wires the new crate into the workspace.

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
crates/chat-cli/src/tui/render.rs	New TUI rendering for message list + input bar and cursor placement.
crates/chat-cli/src/tui/mod.rs	New TUI state + main loop integrating keyboard input and inbound message draining.
crates/chat-cli/src/main.rs	New CLI entrypoint wiring ChatClient to LogosDeliveryService, logging, and TUI startup.
crates/chat-cli/src/delivery/mod.rs	New DeliveryService implementation that runs a logos-delivery node on a background thread and fans out inbound payloads.
crates/chat-cli/src/delivery/sys.rs	Raw FFI declarations + trampoline for callbacks into Rust closures.
crates/chat-cli/src/delivery/wrapper.rs	“Safe synchronous” wrapper around the raw FFI calls + Drop-based shutdown.
crates/chat-cli/build.rs	Links liblogosdelivery (and rpath) when LOGOS_DELIVERY_LIB_DIR is provided.
crates/chat-cli/README.md	End-user build/run/test documentation for the example app and logos-delivery dependency.
crates/chat-cli/Cargo.toml	New crate manifest and dependencies for TUI/CLI/FFI glue.
README.md	Root README updated to point to crates/chat-cli as an example app.
Makefile	Adds top-level build helpers (clone/build logos-delivery, build chat-cli, check/test targets).
Cargo.toml	Adds crates/chat-cli to workspace members.
Cargo.lock	Locks new dependencies brought in by chat-cli.

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[Copilot]

Pull request overview

Adds an example chat-cli binary that can run either on a local file-based transport or (when built with LOGOS_DELIVERY_LIB_DIR) on a logos-delivery (Waku) transport, and wires it into Nix + CI for a basic smoketest.

Changes:

• Add a logos-delivery-backed client::DeliveryService implementation (FFI + wrapper) and a new file transport compatible with client::ChatClient.
• Refactor chat-cli to use client::ChatClient, add clap CLI args, and update the TUI/session model (nicknames, scrolling).
• Extend Nix flake + GitHub Actions CI to build logos-delivery and build/run chat-cli smoketest.

Reviewed changes

Copilot reviewed 12 out of 16 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
flake.nix	Adds logos-delivery input and a patched package output for CI/build usage
flake.lock	Locks logos-delivery (and its dependency graph) for Nix builds
bin/chat-cli/src/ui.rs	Makes UI generic over transport, updates headers, wrapping, and scrolling behavior
bin/chat-cli/src/transport/logos_delivery/wrapper.rs	Safe-ish synchronous wrapper around raw logos-delivery FFI
bin/chat-cli/src/transport/logos_delivery/sys.rs	Raw extern declarations + callback trampoline
bin/chat-cli/src/transport/logos_delivery.rs	Implements DeliveryService using an embedded node thread + JSON event parsing
bin/chat-cli/src/transport/file.rs	New file transport that publishes length-prefixed frames and polls for inbound frames
bin/chat-cli/src/transport.rs	Switches transport modules via cfg(logos_delivery)
bin/chat-cli/src/main.rs	Adds clap CLI, compile-time transport selection, logging setup, and smoketest mode
bin/chat-cli/src/app.rs	Refactors app state around client::ChatClient, conversations by id, nicknames, command output
bin/chat-cli/build.rs	Links liblogosdelivery and sets rpath when LOGOS_DELIVERY_LIB_DIR is set
bin/chat-cli/README.md	Updates build/run docs for both transports and new CLI flags
bin/chat-cli/Cargo.toml	Adds dependencies needed for the new client/transports and cfg linting
README.md	Mentions bin/chat-cli as an example app and provides quick build/run snippet
Cargo.lock	Updates lockfile for new dependencies (clap, tracing, base64, etc.)
.github/workflows/ci.yml	Adds Nix install + builds logos-delivery + builds/runs chat-cli smoketest

Comments suppressed due to low confidence (1)

bin/chat-cli/src/ui.rs:120

• content.split_at(first_line_width) uses a byte index derived from terminal cell width. If msg.content contains non-ASCII UTF-8, this can panic because split_at requires a char boundary (and even if it doesn’t panic, byte length != display width). Prefer splitting on char_indices() / grapheme clusters and measuring display width (e.g., unicode_width) instead of raw len() bytes.

            let mut items = Vec::new();
            let first_line_width = inner_width.saturating_sub(prefix_len).max(1);

            // First line includes the prefix.
            let (first_chunk, rest): (&str, &str) = if content.len() <= first_line_width {
                (content.as_str(), "")
            } else {
                content.split_at(first_line_width)
            };

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[kaichaosun]

I think the feature flag for the app is over kill, we can just enable file transport and logos_delivery, and with a param (like --transport) to decide which transport to use.

LOGOS_DELIVERY_LIB_DIR could use the default ones without explicitly set it when set the logos delivery params, and LOGOS_DELIVERY_LIB_DIR can be configurable if need a different path.

[osmaczko]

I agree, let me address it in the followup PR.

[jazzz]

I've tested it, looks good for a dev app.

[jazzz]

[Dust] This flag seems out of place to me. Naively appears the most value comes from ensuring the build succeeds - if the application returns early.

[kaichaosun]

💯