v0.2.4: diff3 conflict markers for jj, multi-line import merging

Output diff3 format (with ||||||| base section) in standard marker mode
so jj can parse partial resolutions. Fixes "did not produce valid
conflict markers" error. Thanks @ilyagr for the report.

Also adds multi-line import block merging (consolidates specifiers as
sets) and README updates with jj config + mergiraf comparison.

Author: rs545837

README.md

@@ -63,6 +63,18 @@ The same scenario above? Weave merges it cleanly with zero conflicts — both fu
 
 The key difference: Git produces false conflicts on **independent changes** because they happen to be in the same file. Weave only conflicts on **actual semantic collisions** when two branches change the same entity incompatibly.
 
+## Weave vs Mergiraf
+
+Tested on 31 real-world merge scenarios across Python, TypeScript, Rust, Go, Java, and C:
+
+| Tool | Clean Merges | Score |
+|------|-------------|-------|
+| **Weave** | **31/31** | 100% |
+| Mergiraf (v0.16.3) | 26/31 | 83% |
+| Git | 15/31 | 48% |
+
+Mergiraf fails on both-add-at-end-of-file, insert-between-existing, and decorator conflict scenarios. Weave resolves all of these because it operates at entity granularity (functions, classes, methods) rather than AST node level. Full breakdown at [ataraxy-labs.github.io/weave](https://ataraxy-labs.github.io/weave/).
+
 ## Real-World Benchmarks
 
 Tested on real merge commits from major open-source repositories. For each merge commit, we replay the merge with both Git and Weave, then compare against the human-authored result.
@@ -137,6 +149,25 @@ git config merge.weave.driver "weave-driver %O %A %B %L %P"
 echo "*.ts *.tsx *.js *.py *.go *.rs *.java *.c *.cpp *.rb *.cs merge=weave" >> .git/info/attributes
 ```
 
+## Jujutsu (jj)
+
+Add to your jj config (`jj config edit --user`):
+
+```toml
+[merge-tools.weave]
+program = "weave-driver"
+merge-args = ["$base", "$left", "$right", "-o", "$output", "-l", "$marker_length", "-p", "$path"]
+merge-conflict-exit-codes = [1]
+merge-tool-edits-conflict-markers = true
+conflict-marker-style = "git"
+```
+
+Resolve conflicts with `jj resolve --tool weave`, or set as default:
+
+```bash
+jj config set --user ui.merge-editor "weave"
+```
+
 ## Preview
 
 Dry-run a merge to see what weave would do:

crates/weave-cli/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "weave-cli"
-version = "0.2.3"
+version = "0.2.4"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 description = "Entity-level semantic merge CLI. Resolves conflicts at the function/class level instead of lines."
@@ -15,8 +15,8 @@ name = "weave"
 path = "src/main.rs"
 
 [dependencies]
-weave-core = { path = "../weave-core", version = "0.2.3" }
-weave-crdt = { path = "../weave-crdt", version = "0.2.3" }
+weave-core = { path = "../weave-core", version = "0.2.4" }
+weave-crdt = { path = "../weave-crdt", version = "0.2.4" }
 sem-core = "0.3.9"
 clap = { version = "4", features = ["derive"] }
 colored = "3"

crates/weave-core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "weave-core"
-version = "0.2.3"
+version = "0.2.4"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 description = "Entity-level semantic merge engine. Three-way merge at the function/class/method level instead of lines."

crates/weave-core/src/conflict.rs

@@ -375,6 +375,28 @@ impl EntityConflict {
             }
         }
 
+        // Base section for diff3 format (standard mode only)
+        if !fmt.enhanced {
+            let base_marker = "|".repeat(fmt.marker_length);
+            out.push_str(&format!("{} base\n", base_marker));
+            let base = self.base_content.as_deref().unwrap_or("");
+            if has_narrowing {
+                let base_lines: Vec<&str> = base.lines().collect();
+                // Use prefix/suffix from ours/theirs narrowing as approximation
+                let base_prefix = prefix_len.min(base_lines.len());
+                let base_suffix = suffix_len.min(base_lines.len().saturating_sub(base_prefix));
+                for line in &base_lines[base_prefix..base_lines.len() - base_suffix] {
+                    out.push_str(line);
+                    out.push('\n');
+                }
+            } else {
+                out.push_str(base);
+                if !base.is_empty() && !base.ends_with('\n') {
+                    out.push('\n');
+                }
+            }
+        }
+
         out.push_str(&format!("{}\n", sep));
 
         // Theirs content (narrowed or full)
@@ -771,7 +793,7 @@ mod tests {
             base_content: Some("return 0;".to_string()),
         };
         let markers = conflict.to_conflict_markers(&MarkerFormat::standard(7));
-        assert_eq!(markers, "<<<<<<< ours\nreturn 1;\n=======\nreturn 2;\n>>>>>>> theirs\n");
+        assert_eq!(markers, "<<<<<<< ours\nreturn 1;\n||||||| base\nreturn 0;\n=======\nreturn 2;\n>>>>>>> theirs\n");
         // No em-dash, no hint, no metadata
         assert!(!markers.contains('\u{2014}'));
         assert!(!markers.contains("hint"));