docs: tambah doc comment, logging, dan inline comments di semua 255 file

Meliputi:
- File-level //! doc comment: tujuan file, alur kerja, komponen utama
- Function-level /// doc comment: apa, parameter, return, flow, edge cases
- Struct/enum/trait /// doc comment: peran, field docs
- Tracing logging (tracing::info!/debug!/trace!/warn!/error!) di setiap fungsi
- Inline comments untuk variable dan branching logic penting
- Seluruh 8 crates di workspace: zesdex-backend, zesdex-cms, zesdex-entities,
  zesdex-iam, zesdex-infra, zesdex-ipc, zesdex-middleware, zesdex-utils
- Build: 0 errors, 242/242 tests passed

crates/zesdex-cms/src/infrastructure/persistence/memory_repo.rs

@@ -1,11 +1,35 @@
-//! Markdown file–backed `MemoryRepository`.
+//! Markdown file–backed `MemoryRepository` implementation.
 //!
 //! Each memory is stored as a `.md` file with YAML-ish frontmatter.
-//! Filenames are derived from the memory's `name` via slugification.
+//! Filenames are derived from the memory's `name` via slugification
+//! (see `Memory::slugify`).
 //!
-//! Frontmatter fields parsed from `---\n...\n---\n` header:
-//! name, description, kind, created_at, updated_at, lifecycle,
-//! outcome, scope, before, after, provenances
+//! ## File Format
+//! ```text
+//! ---
+//! name: my-memory
+//! description: A useful lesson
+//! kind: lesson
+//! created_at: 1700000000
+//! updated_at: 1700000000
+//! lifecycle: active
+//! outcome: success
+//! scope: global
+//! before: old content
+//! after: new content
+//! provenances: tool1, tool2
+//! ---
+//! Free-form markdown content body...
+//! ```
+//!
+//! ## Data Flow
+//! - `list()`: scan `*.md` files (excluding `MEMORY.md`), return slugs
+//! - `load()`: read file → strip `---\n...\n---\n` frontmatter → parse fields
+//! - `save()`: build frontmatter → write to temp file → rename atomically
+//! - `delete()`: remove file from disk
+//!
+//! ## Atomicity
+//! Writes use temp-file + rename + parent-directory fsync for crash safety.
 
 use std::collections::HashMap;
 use std::io::Write;
@@ -16,7 +40,10 @@ use anyhow::{Context, Result};
 use crate::domain::memory::Memory;
 use crate::domain::repository::MemoryRepository;
 
-/// Persists `Memory` as markdown files with YAML-ish frontmatter.
+/// File-based `MemoryRepository` that stores memories as `.md` files with frontmatter.
+///
+/// Each file has a YAML-ish `---\n...\n---\n` header followed by free-form
+/// markdown content. Filenames are derived from `Memory.name` via slugification.
 #[derive(Debug, Clone, Default)]
 pub struct MarkdownMemoryRepository;
 
@@ -26,7 +53,9 @@ impl MarkdownMemoryRepository {
         Self
     }
 
-    /// Build the frontmatter lines for a memory.
+    /// Build the YAML-ish frontmatter string for a memory.
+    ///
+    /// Only non-empty optional fields are included in the output.
     fn build_frontmatter(memory: &Memory) -> String {
         let outcome_line = memory
             .outcome
@@ -71,7 +100,10 @@ impl MarkdownMemoryRepository {
         )
     }
 
-    /// Parse frontmatter lines into a `HashMap`.
+    /// Parse frontmatter lines into a `HashMap<String, String>`.
+    ///
+    /// Flow: split lines → for each non-empty line, split on first ':' → insert.
+    /// Malformed lines (no ':') are silently skipped.
     fn parse_frontmatter(front: &str) -> HashMap<String, String> {
         front
             .lines()
@@ -82,7 +114,12 @@ impl MarkdownMemoryRepository {
             .collect()
     }
 
-    /// Parse a memory file's contents (frontmatter + body) into a `Memory`.
+    /// Parse a memory file's full contents (frontmatter + body) into a `Memory`.
+    ///
+    /// Flow: strip `---\n` prefix → split on `\n---\n` → parse front half with
+    /// `parse_frontmatter()` → use back half as content body → build Memory.
+    ///
+    /// Returns `InvalidData` error if the frontmatter delimiter is missing.
     fn parse(content: &str) -> std::io::Result<Memory> {
         let content = content.strip_prefix("---\n").unwrap_or(content);
         let parts: Vec<&str> = content.splitn(2, "\n---\n").collect();
@@ -132,6 +169,10 @@ impl MarkdownMemoryRepository {
 }
 
 impl MemoryRepository for MarkdownMemoryRepository {
+    /// List all memory slugs in `memory_dir` by scanning `*.md` files.
+    ///
+    /// Flow: read directory entries → filter `*.md` → strip extension → exclude MEMORY.md.
+    /// Returns empty Vec if the directory doesn't exist.
     fn list(&self, memory_dir: &Path) -> Result<Vec<String>> {
         let Ok(entries) = std::fs::read_dir(memory_dir) else {
             return Ok(Vec::new());
@@ -152,7 +193,11 @@ impl MemoryRepository for MarkdownMemoryRepository {
         Ok(slugs)
     }
 
+    /// Load a single `Memory` by name from `memory_dir`.
+    ///
+    /// Flow: resolve file path → read file → parse frontmatter + body → return Memory.
     fn load(&self, memory_dir: &Path, name: &str) -> Result<Memory> {
+        tracing::debug!("loading memory '{name}'");
         let path = Memory::path(memory_dir, name);
         let content = std::fs::read_to_string(&path)
             .with_context(|| format!("failed to read memory '{name}' at '{}'", path.display()))?;