feat(pen-figma): skeleton crate (bucket A)

crates/pen-figma/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "pen-figma"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+description = "OpenPencil Figma import/export — bucket A in-WASM"
+
+[lib]
+name = "pen_figma"
+path = "src/lib.rs"
+
+[dependencies]
+pen-types = { path = "../pen-types" }
+serde = { workspace = true }
+serde_json = { workspace = true }

crates/pen-figma/src/lib.rs

@@ -0,0 +1,5 @@
+//! OpenPencil Figma adapter.
+
+pub fn placeholder() -> String {
+    format!("pen-figma ({})", pen_types::placeholder())
+}