fix: implement native DOCX export without pandoc dependency

Replace pandoc-based DOCX export with native Rust implementation
using docx-rs crate. DOCX export now works out of the box without
requiring users to install external tools.

Changes:
- Added docx-rs dependency to Cargo.toml
- Implemented export_docx() in exporter.rs
- Removed pandoc subprocess calls from docs.rs
- Uses same markdown parsing as PDF export
- Handles titles, headings, and normal text with appropriate styling

Tested:
- Rust compilation ✓
- Rust formatting ✓
- TypeScript types ✓

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src-tauri/Cargo.lock

@@ -330,6 +330,12 @@ version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
 
+[[package]]
+name = "byteorder-lite"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f1fe948ff07f4bd06c30984e69f5b4899c516a3ef74f34df92a2df2ab535495"
+
 [[package]]
 name = "bytes"
 version = "1.11.1"
@@ -504,6 +510,12 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "color_quant"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d7b894f5411737b7867f4827955924d7c254fc9f4d91a6aad6b097804b1018b"
+
 [[package]]
 name = "combine"
 version = "4.6.7"
@@ -1047,6 +1059,21 @@ dependencies = [
  "litrs",
 ]
 
+[[package]]
+name = "docx-rs"
+version = "0.4.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed73cbf5e1c37baa23f4132569ac1187829f03922c206bd68fe109e3001a343d"
+dependencies = [
+ "base64 0.22.1",
+ "image",
+ "quick-xml 0.36.2",
+ "serde",
+ "serde_json",
+ "thiserror 2.0.18",
+ "zip 0.6.6",
+]
+
 [[package]]
 name = "dom_query"
 version = "0.25.1"
@@ -1228,6 +1255,26 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
+[[package]]
+name = "fax"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f05de7d48f37cd6730705cbca900770cab77a89f413d23e100ad7fad7795a0ab"
+dependencies = [
+ "fax_derive",
+]
+
+[[package]]
+name = "fax_derive"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a0aca10fb742cb43f9e7bb8467c91aa9bcb8e3ffbc6a6f7389bb93ffc920577d"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
 [[package]]
 name = "fdeflate"
 version = "0.3.7"
@@ -1638,6 +1685,16 @@ dependencies = [
  "polyval",
 ]
 
+[[package]]
+name = "gif"
+version = "0.14.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f5df2ba84018d80c213569363bdcd0c64e6933c67fe4c1d60ecf822971a3c35e"
+dependencies = [
+ "color_quant",
+ "weezl",
+]
+
 [[package]]
 name = "gio"
 version = "0.18.4"
@@ -1816,6 +1873,17 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "half"
+version = "2.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6ea2d84b969582b4b1864a92dc5d27cd2b77b622a8d79306834f1be5ba20d84b"
+dependencies = [
+ "cfg-if",
+ "crunchy",
+ "zerocopy",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.12.3"
@@ -2068,7 +2136,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3e795dff5605e0f04bff85ca41b51a96b83e80b281e96231bcaaf1ac35103371"
 dependencies = [
  "byteorder",
- "png",
+ "png 0.17.16",
 ]
 
 [[package]]
@@ -2185,6 +2253,24 @@ dependencies = [
  "icu_properties",
 ]
 
+[[package]]
+name = "image"
+version = "0.25.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85ab80394333c02fe689eaf900ab500fbd0c2213da414687ebf995a65d5a6104"
+dependencies = [
+ "bytemuck",
+ "byteorder-lite",
+ "color_quant",
+ "gif",
+ "moxcms",
+ "num-traits",
+ "png 0.18.1",
+ "tiff",
+ "zune-core",
+ "zune-jpeg",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.9.3"
@@ -2541,7 +2627,7 @@ dependencies = [
  "tar",
  "ureq",
  "vcpkg",
- "zip",
+ "zip 7.2.0",
 ]
 
 [[package]]
@@ -2738,6 +2824,16 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "moxcms"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb85c154ba489f01b25c0d36ae69a87e4a1c73a72631fc6c0eb6dde34a73e44b"
+dependencies = [
+ "num-traits",
+ "pxfm",
+]
+
 [[package]]
 name = "muda"
 version = "0.17.1"
@@ -2753,7 +2849,7 @@ dependencies = [
  "objc2-core-foundation",
  "objc2-foundation",
  "once_cell",
- "png",
+ "png 0.17.16",
  "serde",
  "thiserror 2.0.18",
  "windows-sys 0.60.2",
@@ -3407,7 +3503,7 @@ checksum = "740ebea15c5d1428f910cd1a5f52cebf8d25006245ed8ade92702f4943d91e07"
 dependencies = [
  "base64 0.22.1",
  "indexmap 2.13.0",
- "quick-xml",
+ "quick-xml 0.38.4",
  "serde",
  "time",
 ]
@@ -3425,6 +3521,19 @@ dependencies = [
  "miniz_oxide",
 ]
 
+[[package]]
+name = "png"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60769b8b31b2a9f263dae2776c37b1b28ae246943cf719eb6946a1db05128a61"
+dependencies = [
+ "bitflags 2.11.0",
+ "crc32fast",
+ "fdeflate",
+ "flate2",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "poly1305"
 version = "0.8.0"
@@ -3593,6 +3702,28 @@ dependencies = [
  "psl-types",
 ]
 
+[[package]]
+name = "pxfm"
+version = "0.1.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5a041e753da8b807c9255f28de81879c78c876392ff2469cde94799b2896b9d"
+
+[[package]]
+name = "quick-error"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a993555f31e5a609f617c12db6250dedcac1b0a85076912c436e6fc9b2c8e6a3"
+
+[[package]]
+name = "quick-xml"
+version = "0.36.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7649a7b4df05aed9ea7ec6f628c67c9953a43869b8bc50929569b2999d443fe"
+dependencies = [
+ "encoding_rs",
+ "memchr",
+]
+
 [[package]]
 name = "quick-xml"
 version = "0.38.4"
@@ -5028,7 +5159,7 @@ dependencies = [
  "ico",
  "json-patch",
  "plist",
- "png",
+ "png 0.17.16",
  "proc-macro2",
  "quote",
  "semver",
@@ -5315,6 +5446,7 @@ dependencies = [
  "base64 0.22.1",
  "chrono",
  "dirs 5.0.1",
+ "docx-rs",
  "futures",
  "hex",
  "printpdf",
@@ -5388,6 +5520,20 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "tiff"
+version = "0.11.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b63feaf3343d35b6ca4d50483f94843803b0f51634937cc2ec519fc32232bc52"
+dependencies = [
+ "fax",
+ "flate2",
+ "half",
+ "quick-error",
+ "weezl",
+ "zune-jpeg",
+]
+
 [[package]]
 name = "time"
 version = "0.3.47"
@@ -5763,7 +5909,7 @@ dependencies = [
  "objc2-core-graphics",
  "objc2-foundation",
  "once_cell",
- "png",
+ "png 0.17.16",
  "serde",
  "thiserror 2.0.18",
  "windows-sys 0.60.2",
@@ -7176,6 +7322,18 @@ dependencies = [
  "syn 2.0.117",
 ]
 
+[[package]]
+name = "zip"
+version = "0.6.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "760394e246e4c28189f19d488c058bf16f564016aefac5d32bb1f3b51d5e9261"
+dependencies = [
+ "byteorder",
+ "crc32fast",
+ "crossbeam-utils",
+ "flate2",
+]
+
 [[package]]
 name = "zip"
 version = "7.2.0"
@@ -7213,3 +7371,18 @@ dependencies = [
  "log",
  "simd-adler32",
 ]
+
+[[package]]
+name = "zune-core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb8a0807f7c01457d0379ba880ba6322660448ddebc890ce29bb64da71fb40f9"
+
+[[package]]
+name = "zune-jpeg"
+version = "0.5.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "27bc9d5b815bc103f142aa054f561d9187d191692ec7c2d1e2b4737f8dbd7296"
+dependencies = [
+ "zune-core",
+]

src-tauri/Cargo.toml

@@ -26,6 +26,7 @@ regex = "1"
 aho-corasick = "1"
 uuid = { version = "1", features = ["v7"] }
 printpdf = "0.7"
+docx-rs = "0.4"
 sha2 = { version = "0.10", features = ["std"] }
 hex = "0.4"
 anyhow = "1"

src-tauri/src/commands/docs.rs

@@ -202,37 +202,10 @@ pub async fn export_document(
             path.to_string_lossy().to_string()
         }
         "docx" => {
-            // DOCX export via pandoc
-            let md_path = base_dir.join(format!("{safe_title}_temp.md"));
-            let docx_path = base_dir.join(format!("{safe_title}.docx"));
-
-            // Write markdown to temp file
-            std::fs::write(&md_path, &content_md)
-                .map_err(|e| format!("Failed to write temp markdown: {}", e))?;
-
-            // Use pandoc to convert
-            let output = std::process::Command::new("pandoc")
-                .arg(md_path.to_str().unwrap())
-                .arg("-o")
-                .arg(docx_path.to_str().unwrap())
-                .arg("-f")
-                .arg("markdown")
-                .arg("-t")
-                .arg("docx")
-                .output()
-                .map_err(|e| format!("Failed to run pandoc (is it installed?): {}", e))?;
-
-            // Clean up temp file
-            let _ = std::fs::remove_file(&md_path);
-
-            if !output.status.success() {
-                return Err(format!(
-                    "Pandoc conversion failed: {}",
-                    String::from_utf8_lossy(&output.stderr)
-                ));
-            }
-
-            docx_path.to_string_lossy().to_string()
+            let path = base_dir.join(format!("{safe_title}.docx"));
+            exporter::export_docx(&content_md, &title, path.to_str().unwrap())
+                .map_err(|e| e.to_string())?;
+            path.to_string_lossy().to_string()
         }
         _ => return Err(format!("Unsupported export format: {format}")),
     };

src-tauri/src/docs/exporter.rs

@@ -9,6 +9,40 @@ pub fn export_markdown(content_md: &str, output_path: &str) -> anyhow::Result<()
     Ok(())
 }
 
+pub fn export_docx(content_md: &str, title: &str, output_path: &str) -> anyhow::Result<()> {
+    use docx_rs::*;
+
+    let path = Path::new(output_path);
+    if let Some(parent) = path.parent() {
+        std::fs::create_dir_all(parent)?;
+    }
+
+    let lines = markdown_to_lines(content_md);
+    let mut docx = Docx::new();
+
+    // Add title
+    docx = docx.add_paragraph(Paragraph::new().add_run(Run::new().add_text(title).size(32).bold()));
+
+    for line_info in &lines {
+        if line_info.text.is_empty() {
+            docx = docx.add_paragraph(Paragraph::new());
+            continue;
+        }
+
+        let run = match line_info.style {
+            LineStyle::Title => Run::new().add_text(&line_info.text).size(28).bold(),
+            LineStyle::Heading => Run::new().add_text(&line_info.text).size(22).bold(),
+            LineStyle::Normal => Run::new().add_text(&line_info.text).size(20),
+        };
+
+        docx = docx.add_paragraph(Paragraph::new().add_run(run));
+    }
+
+    let file = std::fs::File::create(path)?;
+    docx.build().pack(file)?;
+    Ok(())
+}
+
 pub fn export_pdf(content_md: &str, title: &str, output_path: &str) -> anyhow::Result<()> {
     use printpdf::*;