feat(dash): improved frontend dashboard (#6)

Co-authored-by: Sharang Parnerkar <parnerkarsharang@gmail.com>
Reviewed-on: #6

src/models/knowledge.rs

@@ -0,0 +1,60 @@
+use serde::{Deserialize, Serialize};
+
+/// The type of file stored in the knowledge base.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum FileKind {
+    /// PDF document
+    Pdf,
+    /// Plain text or markdown file
+    Text,
+    /// Spreadsheet (csv, xlsx)
+    Spreadsheet,
+    /// Source code file
+    Code,
+    /// Image file
+    Image,
+}
+
+impl FileKind {
+    /// Returns the display label for a file kind.
+    pub fn label(&self) -> &'static str {
+        match self {
+            Self::Pdf => "PDF",
+            Self::Text => "Text",
+            Self::Spreadsheet => "Spreadsheet",
+            Self::Code => "Code",
+            Self::Image => "Image",
+        }
+    }
+
+    /// Returns an icon identifier for rendering.
+    pub fn icon(&self) -> &'static str {
+        match self {
+            Self::Pdf => "file-pdf",
+            Self::Text => "file-text",
+            Self::Spreadsheet => "file-spreadsheet",
+            Self::Code => "file-code",
+            Self::Image => "file-image",
+        }
+    }
+}
+
+/// A file stored in the knowledge base for RAG retrieval.
+///
+/// # Fields
+///
+/// * `id` - Unique file identifier
+/// * `name` - Original filename
+/// * `kind` - Type classification of the file
+/// * `size_bytes` - File size in bytes
+/// * `uploaded_at` - ISO 8601 upload timestamp
+/// * `chunk_count` - Number of vector chunks created from this file
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct KnowledgeFile {
+    pub id: String,
+    pub name: String,
+    pub kind: FileKind,
+    pub size_bytes: u64,
+    pub uploaded_at: String,
+    pub chunk_count: u32,
+}