chore: rename quicproquo → quicprochat in Rust workspace

Rename all crate directories, package names, binary names, proto
package/module paths, ALPN strings, env var prefixes, config filenames,
mDNS service names, and plugin ABI symbols from quicproquo/qpq to
quicprochat/qpc.

crates/quicprochat-p2p/Cargo.toml

@@ -0,0 +1,34 @@
+[package]
+name        = "quicprochat-p2p"
+version     = "0.1.0"
+edition.workspace     = true
+description = "P2P transport layer for quicprochat using iroh."
+license     = "Apache-2.0 OR MIT"
+repository.workspace  = true
+
+[features]
+traffic-resistance = []
+
+[lints]
+workspace = true
+
+[dependencies]
+iroh        = "0.96"
+tokio       = { version = "1", features = ["macros", "rt-multi-thread", "time", "sync"] }
+tracing     = "0.1"
+anyhow      = "1"
+
+# Mesh identity & store-and-forward
+quicprochat-core = { path = "../quicprochat-core", default-features = false }
+serde           = { workspace = true }
+serde_json      = { workspace = true }
+sha2            = { workspace = true }
+hex             = { workspace = true }
+
+# Broadcast channels (ChaCha20-Poly1305 symmetric encryption)
+chacha20poly1305 = { workspace = true }
+rand             = { workspace = true }
+zeroize          = { workspace = true }
+
+[dev-dependencies]
+tempfile = "3"