refactor(workspace): timeline API overhaul and extension system cleanup

.agents/skills/arktype/SKILL.md

@@ -1,6 +1,9 @@
 ---
 name: arktype
 description: Arktype patterns for discriminated unions using .merge() and .or(), spread key syntax, and type composition. Use when building union types, combining base schemas with variants, or defining command/event schemas with arktype.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # Arktype Discriminated Unions

.agents/skills/better-auth-best-practices/SKILL.md

@@ -1,12 +1,25 @@
 ---
 name: better-auth-best-practices
 description: Configure Better Auth server and client, set up database adapters, manage sessions, add plugins, and handle environment variables. Use when users mention Better Auth, betterauth, auth.ts, or need to set up TypeScript authentication with email/password, OAuth, or plugin configuration.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # Better Auth Integration Guide
 
 **Always consult [better-auth.com/docs](https://better-auth.com/docs) for code examples and latest API.**
 
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Configure Better Auth server/client setup in TypeScript projects.
+- Wire environment variables, database adapters, and CLI migrations.
+- Set up sessions, cookie cache strategy, and security/rate-limit options.
+- Add and configure Better Auth plugins plus corresponding client plugins.
+- Troubleshoot common Better Auth model, schema, and storage pitfalls.
+
 ---
 
 ## Setup Workflow
@@ -172,4 +185,4 @@ For separate client/server projects: `createAuthClient<typeof auth>()`.
 - [Options Reference](https://better-auth.com/docs/reference/options)
 - [LLMs.txt](https://better-auth.com/llms.txt)
 - [GitHub](https://github.com/better-auth/better-auth)
-- [Init Options Source](https://github.com/better-auth/better-auth/blob/main/packages/core/src/types/init-options.ts)
+- [Init Options Source](https://github.com/better-auth/better-auth/blob/main/packages/core/src/types/init-options.ts)

.agents/skills/better-auth-security-best-practices/SKILL.MD

@@ -1,6 +1,9 @@
 ---
 name: better-auth-security-best-practices
 description: Configure rate limiting, manage auth secrets, set up CSRF protection, define trusted origins, secure sessions and cookies, encrypt OAuth tokens, track IP addresses, and implement audit logging for Better Auth. Use when users need to secure their auth setup, prevent brute force attacks, or harden a Better Auth deployment.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 ## Secret Management

.agents/skills/control-flow/SKILL.md

@@ -1,12 +1,26 @@
 ---
 name: control-flow
 description: Human-readable control flow patterns for early returns, guard clauses, and linearizing nested logic. Use when refactoring nested conditionals, replacing try-catch with linear flow, or restructuring decision logic.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # Human-Readable Control Flow
 
 When refactoring complex control flow, mirror natural human reasoning patterns:
 
+> **Related Skills**: See `refactoring` for systematic code audit methodology including branch collapsing and caller counting.
+
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Refactor nested conditionals into linear guard-clause control flow.
+- Replace mixed `throw`/`return` try-catch logic with readable early returns.
+- Name booleans and branches to read like natural human reasoning.
+- Restructure handlers so failure paths are explicit before the happy path.
+
 1. **Ask the human question first**: "Can I use what I already have?" -> early return for happy path
 2. **Assess the situation**: "What's my current state and what do I need to do?" -> clear, mutually exclusive conditions
 3. **Take action**: "Get what I need" -> consolidated logic at the end

.agents/skills/create-auth-skill/SKILL.md

@@ -1,6 +1,9 @@
 ---
 name: create-auth-skill
 description: Scaffold and implement authentication in TypeScript/JavaScript apps using Better Auth. Detect frameworks, configure database adapters, set up route handlers, add OAuth providers, and create auth UI pages. Use when users want to add login, sign-up, or authentication to a new or existing project with Better Auth.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # Create Auth Skill
@@ -9,6 +12,16 @@ Guide for adding authentication to TypeScript/JavaScript applications using Bett
 
 **For code examples and syntax, see [better-auth.com/docs](https://better-auth.com/docs).**
 
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Add Better Auth login/sign-up to a new or existing TypeScript/JavaScript app.
+- Plan auth implementation by detecting framework, DB, and existing auth stack.
+- Configure `auth.ts`, client setup, route handlers, and migrations.
+- Add OAuth providers, plugins, and auth pages based on project requirements.
+- Migrate incrementally from another auth library to Better Auth.
+
 ---
 
 ## Phase 1: Planning (REQUIRED before implementation)

.agents/skills/define-errors/SKILL.md

@@ -8,6 +8,18 @@ metadata:
 
 # defineErrors
 
+> **Related Skills**: See `error-handling` for trySync/tryAsync usage. See `services-layer` for service architecture and namespace exports.
+
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Define or refactor domain error variants using `defineErrors`.
+- Add error variants that include structured fields and `cause: unknown`.
+- Centralize `extractErrorMessage(cause)` inside variant factories.
+- Infer union and single-variant types via `InferErrors`/`InferError`.
+- Replace old `createTaggedError` and split Err-pair patterns.
+
 ## Import
 
 ```typescript

.agents/skills/documentation/SKILL.md

@@ -1,6 +1,9 @@
 ---
 name: documentation
 description: In-code documentation, folder READMEs, and code comments. Use when writing README.md files, JSDoc comments, or explaining code organization.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # Documentation
@@ -9,6 +12,15 @@ Follow [writing-voice](../writing-voice/SKILL.md) for tone.
 
 Documentation explains **why**, not **what**. Users can read code to see what it does. They need you to explain the reasoning.
 
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Write or update folder `README.md` files with architecture intent.
+- Add JSDoc to public APIs with usage context and examples.
+- Review docs/comments that currently restate code without rationale.
+- Add code comments for non-obvious decisions, constraints, or workarounds.
+
 ## Folder READMEs
 
 Primary job: explain **why** this folder exists and the mental model.

.agents/skills/drizzle-orm/SKILL.md

@@ -1,10 +1,22 @@
 ---
 name: drizzle-orm
 description: Drizzle ORM patterns for type branding and custom types. Use when working with Drizzle column definitions, branded types, or custom type conversions.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # Drizzle ORM Guidelines
 
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Define Drizzle columns that use branded TypeScript string types.
+- Choose between `$type<T>()` and `customType` for column definitions.
+- Remove identity `toDriver`/`fromDriver` conversions that add runtime overhead.
+- Keep data serialized through the storage layer and parse at UI edges.
+
 ## Use $type<T>() for Branded Strings, Not customType
 
 When you need a column with a branded TypeScript type but no actual data transformation, use `$type<T>()` instead of `customType`.

.agents/skills/elysia/SKILL.md

@@ -8,6 +8,16 @@ metadata:
 
 # Elysia.js Patterns (v1.2+)
 
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Write or refactor Elysia handlers to use `status()` responses.
+- Define per-status response schemas for Eden Treaty type safety.
+- Migrate handlers away from `set.status` plus error-object returns.
+- Compose Elysia plugins/guards for shared auth and route behavior.
+- Choose between `return status(...)` and `throw status(...)` by control-flow context.
+
 ## The `status()` Helper (ALWAYS use this)
 
 **Never use `set.status` + return object.** Always destructure `status` from the handler context and use it for all non-200 responses. This gives you:

.agents/skills/email-and-password-best-practices/SKILL.md

@@ -1,8 +1,21 @@
 ---
 name: email-and-password-best-practices
 description: Configure email verification, implement password reset flows, set password policies, and customise hashing algorithms for Better Auth email/password authentication. Use when users need to set up login, sign-in, sign-up, credential authentication, or password security with Better Auth.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Set up Better Auth email/password sign-up and sign-in flows.
+- Implement email verification requirements and delivery hooks.
+- Build password reset request and reset-token handling.
+- Configure password policies, reset token expiry, and session revocation.
+- Customize password hashing/verification algorithms for credential auth.
+
 ## Quick Start
 
 1. Enable email/password: `emailAndPassword: { enabled: true }`

.agents/skills/error-handling/SKILL.md

@@ -8,6 +8,16 @@ metadata:
 
 # Error Handling with wellcrafted trySync and tryAsync
 
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Replace recoverable `try-catch` blocks with `trySync` or `tryAsync`.
+- Handle fallback success paths via `Ok(...)` and propagate failures with `Err(...)`.
+- Wrap caught exceptions as `cause` for typed domain error constructors.
+- Refactor nested error branches into immediate-return linear control flow.
+- Convert handler failures into HTTP status responses with explicit guards.
+
 ## Use trySync/tryAsync Instead of try-catch for Graceful Error Handling
 
 When handling errors that can be gracefully recovered from, use `trySync` (for synchronous code) or `tryAsync` (for asynchronous code) from wellcrafted instead of traditional try-catch blocks. This provides better type safety and explicit error handling.

.agents/skills/factory-function-composition/SKILL.md

@@ -10,6 +10,8 @@ metadata:
 
 This skill helps you apply factory function patterns for clean dependency injection and function composition in TypeScript.
 
+> **Related Skills**: See `method-shorthand-jsdoc` for when to move helpers into the return object. See `refactoring` for caller counting and inlining single-use extractions.
+
 ## When to Apply This Skill
 
 Use this pattern when you see:

.agents/skills/frontend-design/SKILL.md

@@ -1,13 +1,26 @@
 ---
 name: frontend-design
 description: Create distinctive, production-grade frontend interfaces with high design quality. Use this skill when the user asks to build web components, pages, artifacts, posters, or applications (examples include websites, landing pages, dashboards, React components, HTML/CSS layouts, or when styling/beautifying any web UI). Generates creative, polished code and UI design that avoids generic AI aesthetics.
+metadata:
+  author: epicenter
+  version: '1.0'
 license: Complete terms in LICENSE.txt
 ---
 
 This skill guides creation of distinctive, production-grade frontend interfaces that avoid generic "AI slop" aesthetics. Implement real working code with exceptional attention to aesthetic details and creative choices.
 
 The user provides frontend requirements: a component, page, application, or interface to build. They may include context about the purpose, audience, or technical constraints.
 
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Build or redesign a frontend component, page, or full interface.
+- Define and execute a strong aesthetic direction before coding.
+- Produce polished UI with intentional typography, color, motion, and composition.
+- Avoid generic, repetitive AI-style design choices.
+- Match implementation complexity to the chosen visual direction.
+
 ## Design Thinking
 
 Before coding, understand the context and commit to a BOLD aesthetic direction:

.agents/skills/git/SKILL.md

@@ -1,10 +1,25 @@
 ---
 name: git
 description: Git commit and pull request guidelines using conventional commits. Use when creating commits, writing commit messages, creating PRs, or reviewing PR descriptions.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # Git Commit and Pull Request Guidelines
 
+> **Related Skills**: See `incremental-commits` for breaking multi-file changes into atomic commits.
+
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Write commit messages that follow conventional commit rules.
+- Decide commit type/scope formatting and breaking-change notation.
+- Draft PR descriptions that open with WHAT then WHY.
+- Add required user-facing changelog entries for `feat:`/`fix:` PRs.
+- Review commit/PR text for anti-patterns like AI/tool attribution.
+
 ## Conventional Commits Format
 
 ```

.agents/skills/github-issues/SKILL.md

@@ -1,10 +1,23 @@
 ---
 name: github-issues
 description: GitHub issue comment guidelines for community interaction. Use when responding to GitHub issues, bug reports, feature requests, or any GitHub discussion.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # GitHub Issue & PR Comment Guidelines
 
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Reply to GitHub issues, PR threads, or feature/bug discussions.
+- Write acknowledgments, follow-up questions, and troubleshooting replies.
+- Announce fixes with clear credit and community-friendly tone.
+- Offer direct debugging help with scheduling links when needed.
+- Avoid over-structured, corporate-style comment responses.
+
 ## Anti-Patterns (Avoid These)
 
 - **Over-structured responses**: Don't use headers, numbered sections, or bullet lists for simple replies. A conversational paragraph is usually better.

.agents/skills/honesty/SKILL.md

@@ -1,10 +1,21 @@
 ---
 name: honesty
 description: Behavioral guideline for providing brutally honest feedback. Use always - this skill defines core interaction expectations for code review and technical discussions.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # Honesty
 
 Be brutally honest, don't be a yes man.
 If I am wrong, point it out bluntly.
 I need honest feedback on my code.
+
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Review code and call out flawed decisions directly.
+- Correct incorrect assumptions instead of politely agreeing.
+- Give blunt technical feedback in design or implementation discussions.

.agents/skills/incremental-commits/SKILL.md

@@ -1,12 +1,17 @@
 ---
 name: incremental-commits
 description: Break multi-file changes into atomic commits ordered by dependency. Use for refactors, breaking API changes, or features touching 3+ files.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # Incremental Commits
 
 When a feature touches multiple files, implement in **waves**. Each wave is one logical concern, one commit. This creates a clean git history that tells a story.
 
+> **Related Skills**: See `git` for commit message conventions and PR guidelines.
+
 ## The Pattern
 
 ```

.agents/skills/method-shorthand-jsdoc/SKILL.md

@@ -10,6 +10,8 @@ metadata:
 
 When factory functions have helper functions that are only used by returned methods, move them INTO the return object using method shorthand. This ensures JSDoc comments are properly passed through to consumers.
 
+> **Related Skills**: See `factory-function-composition` for the four-zone factory anatomy and the `this` decision rule.
+
 ## The Problem
 
 You write a factory function with a well-documented helper:

.agents/skills/monorepo/SKILL.md

@@ -1,12 +1,23 @@
 ---
 name: monorepo
 description: Monorepo script commands and conventions for this codebase. Use when running builds, tests, formatting, linting, or type checking.
+metadata:
+  author: epicenter
+  version: '1.0'
 ---
 
 # Script Commands
 
 The monorepo uses consistent script naming conventions:
 
+## When to Apply This Skill
+
+Use this pattern when you need to:
+
+- Run formatting, linting, or type-check scripts in this monorepo.
+- Choose between auto-fix commands and `:check` CI-only variants.
+- Verify final changes with the repo-standard `bun typecheck` workflow.
+
 | Command            | Purpose                                        | When to use |
 | ------------------ | ---------------------------------------------- | ----------- |
 | `bun format`       | **Fix** formatting (biome)                     | Development |