diff --git a/scratchpad/architecture.md b/scratchpad/architecture.md
index 96c273aa858..e90e202a938 100644
--- a/scratchpad/architecture.md
+++ b/scratchpad/architecture.md
@@ -1,6 +1,6 @@
 # Architecture Diagram
 
-> Last updated: 2026-04-04 · Source: Issue (see PR for link)
+> Last updated: 2026-04-05 · Source: [Issue #aw_arch001](https://github.com/github/gh-aw/issues)
 
 ## Overview
 
@@ -35,9 +35,9 @@ This diagram shows the package structure and dependencies of the `gh-aw` codebas
 │  ┌──────────┐ ┌──────────────┐ ┌────────────┐ ┌───────────┐ ┌──────────┐ ┌──────────┐            │
 │  │pkg/logger│ │pkg/stringutil│ │pkg/fileutil│ │pkg/gitutil│ │pkg/styles│ │  pkg/tty │            │
 │  └──────────┘ └──────────────┘ └────────────┘ └───────────┘ └──────────┘ └──────────┘            │
-│  ┌───────────┐ ┌─────────────┐ ┌─────────────┐ ┌──────────────┐ ┌────────────┐ ┌────────────┐   │
-│  │pkg/envutil│ │pkg/repoutil │ │pkg/sliceutil│ │pkg/semverutil│ │pkg/timeutil│ │pkg/mathutil│   │
-│  └───────────┘ └─────────────┘ └─────────────┘ └──────────────┘ └────────────┘ └────────────┘   │
+│  ┌───────────┐ ┌─────────────┐ ┌─────────────┐ ┌──────────────┐ ┌────────────┐                   │
+│  │pkg/envutil│ │pkg/repoutil │ │pkg/sliceutil│ │pkg/semverutil│ │pkg/timeutil│                   │
+│  └───────────┘ └─────────────┘ └─────────────┘ └──────────────┘ └────────────┘                   │
 │  ┌──────────────┐                                                                                  │
 │  │ pkg/testutil │  (test support only)                                                            │
 │  └──────────────┘                                                                                  │
@@ -70,5 +70,4 @@ This diagram shows the package structure and dependencies of the `gh-aw` codebas
 | pkg/sliceutil | Utility | Generic slice utility functions |
 | pkg/semverutil | Utility | Semantic versioning primitives |
 | pkg/timeutil | Utility | Time formatting utilities |
-| pkg/mathutil | Utility | Basic mathematical utility functions |
 | pkg/testutil | Utility | Test support utilities (test-only) |