fix: deterministic SundialKitStream stream tests; migrate FitnessStream & Sundial example to mise

SundialKitStream: rewrite pathStatusStream / isExpensiveStream /
isConstrainedStream tests to drive the stream with an async iterator
(await first value, send, await second) instead of confirmation + fixed
Task.sleep delays. The old tests raced the background subscriber's
continuation registration against the second path update on slower CI
runners (Xcode 26.5 / 16.3), capturing only one value -> count==2 failed
-> values[1] crashed the whole xctest process. The iterator approach is
timing-independent. No production code changes.

Mint -> mise migration (matches root / SundialKitStream / SundialKit):
- FitnessStream: add .mise.toml (swift-format 602.0.0, SwiftLint 0.63.3,
  periphery 3.7.4), rewrite Scripts/lint.sh to use `mise exec`, switch the
  CI lint job to jdx/mise-action, delete Mintfile, update docs. Lint
  strictness left non-strict to preserve prior CI behavior.
- SundialKit Examples/Sundial: add .mise.toml (swift-protobuf 1.38.0),
  rewrite generate-protos.sh to resolve protoc/protoc-gen-swift via mise
  (no system protoc required), delete Mintfile, update docs.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: leogdion

Examples/Sundial/.mise.toml

@@ -0,0 +1,6 @@
+[tools]
+# Protocol Buffer Swift plugin (migrated from Mint)
+"spm:apple/swift-protobuf" = "1.38.0"
+
+[settings]
+experimental = true

Examples/Sundial/Documentation/RESUME_HERE.md

@@ -18,7 +18,7 @@
 - ✅ Build scripts and documentation
 
 ### Shared UI Components (Phase 2) ✅ NEW!
-- ✅ Mint setup for swift-protobuf tools (Mintfile)
+- ✅ mise setup for swift-protobuf tools (.mise.toml)
 - ✅ Generated Swift code from .proto schemas (3 files)
 - ✅ MetricCard.swift - Reusable metric display
 - ✅ ColorPreview.swift - Color circle with metadata
@@ -59,9 +59,9 @@ Documentation/
   └── RESUME_HERE.md (this file)
 
 Scripts/
-  └── generate-protos.sh                   ✅ UPDATED (uses Mint)
+  └── generate-protos.sh                   ✅ UPDATED (uses mise)
 
-Mintfile                                    ✅ NEW!
+.mise.toml                                  ✅ NEW!
 Package.swift
 Package.resolved                            ✅ NEW!
 README.md

Examples/Sundial/Mintfile

@@ -23,42 +23,25 @@ OUTPUT_DIR="$PROJECT_DIR/Sources/Shared/Generated"
 
 echo -e "${GREEN}Generating Swift code from Protocol Buffers...${NC}"
 
-# Detect OS and set Mint path
-if [ "$(uname)" = "Darwin" ]; then
-    DEFAULT_MINT_PATH="/opt/homebrew/bin/mint"
-elif [ "$(uname)" = "Linux" ] && [ -n "$GITHUB_ACTIONS" ]; then
-    DEFAULT_MINT_PATH="$GITHUB_WORKSPACE/Mint/.mint/bin/mint"
-elif [ "$(uname)" = "Linux" ]; then
-    DEFAULT_MINT_PATH="/usr/local/bin/mint"
-else
-    echo -e "${RED}Unsupported operating system${NC}"
-    exit 1
-fi
-
-# Use environment MINT_CMD if set, otherwise use default path
-MINT_CMD=${MINT_CMD:-$DEFAULT_MINT_PATH}
-
-# Check if Mint is installed
-if ! command -v "$MINT_CMD" &> /dev/null; then
-    echo -e "${RED}Error: Mint not found at $MINT_CMD${NC}"
-    echo "Install with: brew install mint"
+# Check if mise is installed
+if ! command -v mise &> /dev/null; then
+    echo -e "${RED}Error: mise not found${NC}"
+    echo "Install mise: https://mise.jdx.dev/getting-started.html"
     exit 1
 fi
 
-# Set up Mint environment
-export MINT_PATH="$PROJECT_DIR/.mint"
-MINT_ARGS="-n -m $PROJECT_DIR/Mintfile --silent"
-MINT_RUN="$MINT_CMD run $MINT_ARGS"
+# Install pinned tools (reads .mise.toml). swift-protobuf provides both
+# protoc and the protoc-gen-swift plugin, so no system protoc is required.
+echo "Installing swift-protobuf via mise..."
+(cd "$PROJECT_DIR" && mise install)
 
-# Bootstrap Mint packages
-echo "Installing swift-protobuf via Mint..."
-$MINT_CMD bootstrap -m "$PROJECT_DIR/Mintfile"
+# Expose the mise-managed bin dir (contains protoc and protoc-gen-swift)
+PLUGIN_DIR="$( cd "$PROJECT_DIR" && dirname "$(mise which protoc-gen-swift)" )"
 
-# Check if protoc is installed
-if ! command -v protoc &> /dev/null; then
-    echo -e "${RED}Error: protoc not found${NC}"
-    echo "Install with: brew install protobuf"
-    echo "Or download from: https://github.com/protocolbuffers/protobuf/releases"
+# Verify protoc is available via mise
+if [ ! -x "$PLUGIN_DIR/protoc" ]; then
+    echo -e "${RED}Error: protoc not found in mise tools at $PLUGIN_DIR${NC}"
+    echo "Ensure swift-protobuf is installed: (cd $PROJECT_DIR && mise install)"
     exit 1
 fi
 
@@ -70,10 +53,10 @@ echo "Input:  $PROTO_DIR"
 echo "Output: $OUTPUT_DIR"
 echo ""
 
-# Run protoc with Mint-managed plugin in PATH
-# Mint installs protoc-gen-swift to .mint/bin/ which protoc will find via PATH
+# Run protoc with the mise-managed plugin in PATH
+# protoc discovers protoc-gen-swift via PATH
 # Visibility=Public ensures generated types are accessible from other modules
-PATH="$MINT_PATH/bin:$PATH" protoc \
+PATH="$PLUGIN_DIR:$PATH" protoc \
   --swift_out=Visibility=Public:"$OUTPUT_DIR" \
   --proto_path="$PROTO_DIR" \
   "$PROTO_DIR"/*.proto