docs: Restructure AGENTS.md style guide with organized sections and code examples

AGENTS.md

@@ -5,8 +5,9 @@
 
 ## Style Guide
 
+### General Principles
+
 - Keep things in one function unless composable or reusable
-- Avoid unnecessary destructuring. Instead of `const { a, b } = obj`, use `obj.a` and `obj.b` to preserve context
 - Avoid `try`/`catch` where possible
 - Avoid using the `any` type
 - Prefer single word variable names where possible
@@ -14,70 +15,97 @@
 - Rely on type inference when possible; avoid explicit type annotations or interfaces unless necessary for exports or clarity
 - Prefer functional array methods (flatMap, filter, map) over for loops; use type guards on filter to maintain type inference downstream
 
-### Avoid let statements
+### Naming
 
-We don't like `let` statements, especially combined with if/else statements.
+Prefer single word names for variables and functions. Only use multiple words if necessary.
-Prefer `const`.
-
-Good:
 
 ```ts
-const foo = condition ? 1 : 2
+// Good
+const foo = 1
+function journal(dir: string) {}
+
+// Bad
+const fooBar = 1
+function prepareJournal(dir: string) {}
 ```
 
-Bad:
+Reduce total variable count by inlining when a value is only used once.
 
 ```ts
-let foo
+// Good
+const journal = await Bun.file(path.join(dir, "journal.json")).json()
 
+// Bad
+const journalPath = path.join(dir, "journal.json")
+const journal = await Bun.file(journalPath).json()
+```
+
+### Destructuring
+
+Avoid unnecessary destructuring. Use dot notation to preserve context.
+
+```ts
+// Good
+obj.a
+obj.b
+
+// Bad
+const { a, b } = obj
+```
+
+### Variables
+
+Prefer `const` over `let`. Use ternaries or early returns instead of reassignment.
+
+```ts
+// Good
+const foo = condition ? 1 : 2
+
+// Bad
+let foo
 if (condition) foo = 1
 else foo = 2
 ```
 
-### Avoid else statements
+### Control Flow
 
-Prefer early returns or using an `iife` to avoid else statements.
+Avoid `else` statements. Prefer early returns.
-
-Good:
 
 ```ts
+// Good
 function foo() {
   if (condition) return 1
   return 2
 }
-```
 
-Bad:
+// Bad
-
-```ts
 function foo() {
   if (condition) return 1
   else return 2
 }
 ```
 
-### Prefer single word naming
+### Schema Definitions (Drizzle)
 
-Try your best to find a single word name for your variables, functions, etc.
+Use snake_case for field names so column names don't need to be redefined as strings.
-Only use multiple words if you cannot.
-
-Good:
 
 ```ts
-const foo = 1
+// Good
-const bar = 2
+const table = sqliteTable("session", {
-const baz = 3
+  id: text().primaryKey(),
-```
+  project_id: text().notNull(),
+  created_at: integer().notNull(),
+})
 
-Bad:
+// Bad
-
+const table = sqliteTable("session", {
-```ts
+  id: text("id").primaryKey(),
-const fooBar = 1
+  projectID: text("project_id").notNull(),
-const barBaz = 2
+  createdAt: integer("created_at").notNull(),
-const bazFoo = 3
+})
 ```
 
 ## Testing
 
-You MUST avoid using `mocks` as much as possible.
+- Avoid mocks as much as possible
-Tests MUST test actual implementation, do not duplicate logic into a test.
+- Test actual implementation, do not duplicate logic into tests