Milestone 1: workspace skeleton, wire protocol, socket round-trip

Three-crate workspace per SPECS.md. varde-proto defines the full JSON
Lines protocol (requests, envelopes, structured errors, events) with
string-typed hashes so the crate carries no iroh dependency. The daemon
binds its unix socket, loads config with flags > env > file > defaults
precedence, and answers status/list; everything else returns a
structured "unimplemented" error. varde-ctl maps subcommands 1:1 onto
requests and round-trips status against a real daemon in the tests.

Dependencies: serde/serde_json (wire format), tokio (async runtime and
unix sockets), tracing/tracing-subscriber (structured logging), toml
(config file), anyhow (binary-edge errors), thiserror (reserved for
library errors), clap (ctl flag parsing, per spec), tempfile (dev-only,
ephemeral test dirs).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.ci/woodpecker.yaml

@@ -0,0 +1,22 @@
+# Woodpecker CI pipeline. Also parseable by eye as the definition of the
+# project quality bar: fmt, clippy -D warnings, full test suite.
+when:
+  - event: [push, pull_request]
+
+steps:
+  fmt:
+    image: rust:1
+    commands:
+      - rustup component add rustfmt
+      - cargo fmt --all --check
+
+  clippy:
+    image: rust:1
+    commands:
+      - rustup component add clippy
+      - cargo clippy --workspace --all-targets -- -D warnings
+
+  test:
+    image: rust:1
+    commands:
+      - cargo test --workspace