Add Makefile with build, test, run, and devrun targets

Makefile wraps Gradle commands and adds emulator/device launch targets:
- run: builds, starts DC-1 emulator if needed, installs and launches
- devrun: builds, installs and launches on connected USB device
- Updated CLAUDE.md and DESIGN.md source trees

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -9,13 +9,17 @@ eng-pad is an Android note-taking app built around notebooks with an EMR pen as
 ## Build Commands
 
 ```bash
-./gradlew build          # Compile everything
+make all                 # lint → test → build
-./gradlew test           # Run unit tests
+make build               # Compile debug + release APKs
-./gradlew lint           # Run Android Lint
+make test                # Run unit tests
-./gradlew installDebug   # Install debug APK to connected device
+make lint                # Run Android Lint
+make clean               # Clean build artifacts
+make run                 # Build, install, and launch on emulator (starts emulator if needed)
+make devrun              # Build, install, and launch on connected USB device
+make run AVD=Medium_Phone_API_36.0  # Use a specific AVD
 
 # Run a single test class:
-./gradlew test --tests "net.metacircular.engpad.data.StrokeBlobTest"
+make test-one CLASS=net.metacircular.engpad.data.StrokeBlobTest
 ```
 
 ## Architecture
@@ -62,9 +66,10 @@ eng-pad/
 │       │   └── res/
 │       └── test/                                     -- Unit tests
 ├── build.gradle.kts                                  -- Root build config
-├── settings.gradle.kts
+├── settings.gradle.kts                               -- Project settings (foojay JDK resolver)
 ├── gradle.properties
 ├── gradle/libs.versions.toml                         -- Version catalog
+├── Makefile                                          -- Build targets (build, test, lint, run, devrun)
 ├── CLAUDE.md                                         -- This file
 ├── README.md
 ├── DESIGN.md                                         -- Technical design

DESIGN.md

@@ -190,7 +190,7 @@ The editor toolbar controls the active mode:
    redrawn only when strokes change (add, delete, move).
 2. **In-progress stroke** (pen is down) is drawn directly to the canvas on
    each `onDraw` call, on top of the backing bitmap.
-3. **Grid** is drawn as a separate pass — thin gray lines at 14.4pt intervals.
+3. **Grid** is drawn as a separate pass — thin gray lines at 60pt intervals.
 4. The view `Matrix` transforms everything from canonical to screen space.
 
 This approach means `onDraw` is fast for the common case (pen moving):
@@ -317,14 +317,15 @@ eng-pad/
 │           └── kotlin/net/metacircular/engpad/
 │               ├── data/
 │               │   ├── StrokeBlobTest.kt             -- Float array ↔ blob roundtrip
-│               │   └── RepositoryTest.kt             -- CRUD + cascade delete
+│               │   └── PageSizeTest.kt               -- Page size enum tests
 │               └── undo/
 │                   └── UndoManagerTest.kt            -- Undo/redo logic
 ├── build.gradle.kts                                  -- Root build config
-├── settings.gradle.kts                               -- Project settings
+├── settings.gradle.kts                               -- Project settings (foojay JDK resolver)
 ├── gradle.properties                                 -- Gradle properties
 ├── gradle/
 │   └── libs.versions.toml                            -- Version catalog
+├── Makefile                                          -- Build targets (build, test, lint, run, devrun)
 ├── .gitignore
 ├── CLAUDE.md
 ├── README.md

Makefile

@@ -0,0 +1,48 @@
+ANDROID_HOME ?= $(HOME)/Library/Android/sdk
+ADB          := $(ANDROID_HOME)/platform-tools/adb
+EMULATOR     := $(ANDROID_HOME)/emulator/emulator
+AVD          ?= DC-1
+PACKAGE      := net.metacircular.engpad
+ACTIVITY     := $(PACKAGE).MainActivity
+
+.PHONY: build test lint clean run devrun all
+
+# Build everything (compile + test + lint)
+all: lint test build
+
+# Compile debug and release APKs
+build:
+	./gradlew build
+
+# Run unit tests
+test:
+	./gradlew test
+
+# Run a single test class: make test-one CLASS=net.metacircular.engpad.data.StrokeBlobTest
+test-one:
+	./gradlew test --tests "$(CLASS)"
+
+# Run Android lint
+lint:
+	./gradlew lint
+
+# Clean build artifacts
+clean:
+	./gradlew clean
+
+# Install and launch on the Android emulator.
+# Starts the emulator if it isn't already running.
+run: build
+	@if ! $(ADB) devices | grep -q emulator; then \
+		echo "Starting emulator ($(AVD))..."; \
+		$(EMULATOR) -avd $(AVD) -no-snapshot-load &>/dev/null & \
+		$(ADB) wait-for-device; \
+		echo "Emulator ready."; \
+	fi
+	./gradlew installDebug
+	$(ADB) -e shell am start -n $(PACKAGE)/$(ACTIVITY)
+
+# Install and launch on a connected USB device.
+devrun: build
+	./gradlew installDebug
+	$(ADB) -d shell am start -n $(PACKAGE)/$(ACTIVITY)