initial project scaffold

Rust workspace with nomina-core (rename engine) and nomina-app (Tauri v2 shell).
React/TypeScript frontend with tabbed rule panels, virtual-scrolled file list,
and Zustand state management. All 9 rule types implemented with 25 passing tests.

crates/nomina-core/src/lib.rs

@@ -0,0 +1,107 @@
+pub mod rules;
+pub mod pipeline;
+pub mod filter;
+pub mod metadata;
+pub mod preset;
+pub mod undo;
+pub mod scanner;
+
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use std::path::PathBuf;
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum NominaError {
+    #[error("Invalid regex pattern: {pattern} - {reason}")]
+    InvalidRegex { pattern: String, reason: String },
+
+    #[error("File not found: {path}")]
+    FileNotFound { path: PathBuf },
+
+    #[error("Rename conflict: {count} files would produce the name '{name}'")]
+    NamingConflict { name: String, count: usize },
+
+    #[error("Invalid filename '{name}': {reason}")]
+    InvalidFilename { name: String, reason: String },
+
+    #[error("Filesystem error on '{path}': {source}")]
+    Filesystem {
+        path: PathBuf,
+        #[source]
+        source: std::io::Error,
+    },
+
+    #[error("Preset parse error: {reason}")]
+    PresetError { reason: String },
+
+    #[error("BRU import error at line {line}: {reason}")]
+    BruImportError { line: usize, reason: String },
+
+    #[error("EXIF read error for '{path}': {reason}")]
+    ExifError { path: PathBuf, reason: String },
+}
+
+pub type Result<T> = std::result::Result<T, NominaError>;
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct RenameContext {
+    pub index: usize,
+    pub total: usize,
+    pub original_name: String,
+    pub extension: String,
+    pub path: PathBuf,
+    pub size: u64,
+    pub created: Option<DateTime<Utc>>,
+    pub modified: Option<DateTime<Utc>>,
+    pub date_taken: Option<DateTime<Utc>>,
+    pub parent_folder: String,
+}
+
+impl RenameContext {
+    pub fn dummy(index: usize) -> Self {
+        Self {
+            index,
+            total: 1,
+            original_name: String::new(),
+            extension: String::new(),
+            path: PathBuf::new(),
+            size: 0,
+            created: None,
+            modified: None,
+            date_taken: None,
+            parent_folder: String::new(),
+        }
+    }
+}
+
+pub trait RenameRule: Send + Sync {
+    fn apply(&self, filename: &str, context: &RenameContext) -> String;
+    fn display_name(&self) -> &str;
+    fn rule_type(&self) -> &str;
+    fn is_enabled(&self) -> bool;
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct FileEntry {
+    pub path: PathBuf,
+    pub name: String,
+    pub stem: String,
+    pub extension: String,
+    pub size: u64,
+    pub is_dir: bool,
+    pub is_hidden: bool,
+    pub created: Option<DateTime<Utc>>,
+    pub modified: Option<DateTime<Utc>>,
+    pub accessed: Option<DateTime<Utc>>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct PreviewResult {
+    pub original_path: PathBuf,
+    pub original_name: String,
+    pub new_name: String,
+    pub has_conflict: bool,
+    pub has_error: bool,
+    pub error_message: Option<String>,
+}