feat(cli): add weave apply to materialize entity edits onto files

crates/weave-cli/src/commands/apply.rs

@@ -0,0 +1,51 @@
+use colored::Colorize;
+use weave_core::git::find_repo_root;
+use weave_crdt::{reconstruct_file_from_crdt, EntityStateDoc};
+
+/// Materialize entity edits from the CRDT back onto the working files.
+///
+/// This is weave's write side: the CRDT is the authoritative source of an
+/// entity's content, and this projects that content onto disk, reassembling
+/// the file from its entities plus the interstitial text between them. It is
+/// the counterpart to editing entities in the CRDT (via the MCP tools or
+/// `weave claim` flows): edit entities, then `weave apply` to write the files.
+pub fn run(files: &[String]) -> Result<(), Box<dyn std::error::Error>> {
+    if files.is_empty() {
+        return Err("Specify one or more files to apply, e.g. `weave apply src/lib.rs`".into());
+    }
+
+    let repo_root = find_repo_root()?;
+    let state_path = repo_root.join(".weave").join("state.automerge");
+    let state = EntityStateDoc::open(&state_path)?;
+
+    let mut applied = 0usize;
+    for file in files {
+        let reconstructed = reconstruct_file_from_crdt(&state, file)?;
+        if reconstructed.is_empty() {
+            println!(
+                "  {} {} — no entities tracked in the CRDT, skipping",
+                "!".yellow().bold(),
+                file
+            );
+            continue;
+        }
+
+        let target = repo_root.join(file);
+        let before = std::fs::read_to_string(&target).unwrap_or_default();
+        if before == reconstructed {
+            println!("  {} {} — already up to date", "·".dimmed(), file);
+            continue;
+        }
+
+        std::fs::write(&target, &reconstructed)?;
+        applied += 1;
+        println!("  {} {} — materialized from CRDT", "✓".green().bold(), file);
+    }
+
+    println!(
+        "{} {} file(s) written from the CRDT.",
+        "weave apply:".bold(),
+        applied
+    );
+    Ok(())
+}

crates/weave-cli/src/commands/mod.rs

@@ -1,3 +1,4 @@
+pub mod apply;
 pub mod bench;
 pub mod bench_repo;
 pub mod claim;

crates/weave-cli/src/main.rs

@@ -26,6 +26,11 @@ enum Commands {
     },
     /// Remove weave merge driver from the current Git repo
     Unsetup,
+    /// Materialize entity edits from the CRDT back onto the working files
+    Apply {
+        /// One or more files to write from the CRDT
+        files: Vec<String>,
+    },
     /// Preview what a merge between branches would look like
     Preview {
         /// The branch to merge into HEAD
@@ -99,6 +104,7 @@ fn main() {
             global,
         } => commands::setup::run(driver.as_deref(), local, global),
         Commands::Unsetup => commands::setup::unsetup(),
+        Commands::Apply { ref files } => commands::apply::run(files),
         Commands::Preview {
             ref branch,
             ref file,