Feature/go runner error handling

.gitignore

@@ -133,6 +133,7 @@ dist/
 .pnp.*
 
 # Generated files
+chart-data.json
 out/chart-data.json
 out/chart-config.json
 out/e2e-*-output.json
@@ -230,3 +231,10 @@ testdata/*-output.json
 # Contribot
 contribot.*.json
 transcripts/
+
+.playwright-cli
+# Editor and tool artifacts
+*.backup
+
+# Claude Code agent artifacts
+.claude/scheduled_tasks.lock

.interface-design/system.md

@@ -0,0 +1,129 @@
+# Design System
+
+## File Structure
+
+```
+out/css/tokens.css   — CSS custom properties (single source of truth for all tokens)
+out/css/styles.css   — component styles (@import ./tokens.css; zero hardcoded values)
+out/index.html       — <link rel="stylesheet" href="css/styles.css" />
+```
+
+Dependency graph: `index.html → styles.css → tokens.css`
+
+## Tokens (`out/css/tokens.css`)
+
+### Surfaces
+| Token | Value | Usage |
+|---|---|---|
+| `--surface-base` | `#0f172a` | Deepest bg: body gradient start, table `<th>` |
+| `--surface-card` | `#1a2035` | Section bg: `.trades-section`, `.info` |
+| `--surface-raised` | `#1e293b` | Card bg: `#container`, `.chart-container` |
+| `--surface-raised-alpha` | `rgba(30,41,59,0.85)` | Fullscreen toggle button bg |
+| `--surface-hover` | `rgba(255,255,255,0.06)` | Row hover — visible on any dark surface |
+
+### Borders
+| Token | Value | Usage |
+|---|---|---|
+| `--border-subtle` | `#2d3748` | Inner dividers, row borders, section internals |
+| `--border-default` | `#334155` | Outer borders: container, chart, buttons |
+
+### Text
+| Token | Value | Usage |
+|---|---|---|
+| `--text-primary` | `#cbd5e1` | Body text, card text |
+| `--text-secondary` | `#94a3b8` | `<th>`, summary, button default label |
+| `--text-muted` | `#6b7280` | Timestamp, `.no-trades` placeholder |
+
+### Accent
+| Token | Value | Usage |
+|---|---|---|
+| `--color-accent` | `#5eead4` | Section headings, hover state, focus ring |
+| `--color-accent-alt` | `#2dd4bf` | h1 gradient end |
+| `--color-accent-subtle` | `rgba(94,234,212,0.25)` | Pane resize handle hover fill |
+
+### Actions
+| Token | Value | Usage |
+|---|---|---|
+| `--color-action` | `#2563eb` | `.refresh-btn` bg |
+| `--color-action-hover` | `#1d4ed8` | `.refresh-btn:hover` bg |
+
+### Semantic
+| Token | Value | Usage |
+|---|---|---|
+| `--color-long` | `#10b981` | Long direction, positive P/L |
+| `--color-short` | `#ef4444` | Short direction, negative P/L |
+| `--color-open` | `#3b82f6` | Open / in-progress trades |
+
+### Trade Table
+| Token | Value | Usage |
+|---|---|---|
+| `--stripe-tint` | `rgba(255,255,255,0.03)` | Alternating trade-pair row tint |
+
+### Typography
+| Token | Value | Usage |
+|---|---|---|
+| `--font-ui` | `'Segoe UI', system-ui, sans-serif` | All text |
+
+### Border Radius
+| Token | Value | Usage |
+|---|---|---|
+| `--radius-md` | `6px` | Most elements |
+| `--radius-lg` | `8px` | Outer `#container` only |
+
+### Shadows
+| Token | Value | Usage |
+|---|---|---|
+| `--shadow-container` | `0 4px 6px -1px rgba(0,0,0,0.2)` | `#container` only |
+| `--shadow-text` | `0 2px 4px rgba(0,0,0,0.3)` | `h1` text-shadow |
+
+### Transitions
+| Token | Value | Usage |
+|---|---|---|
+| `--transition-duration` | `0.2s` | All interactive elements |
+
+## Spacing Scale
+Rem-based: `0.5rem`, `0.75rem`, `1rem`, `1.25rem`, `1.5rem`, `2rem`, `2.5rem`
+Pixel exceptions: `8px` (absolute inset positioning only)
+
+## Font Scale
+| Size | Usage |
+|---|---|
+| `2.5rem` | `h1` page title |
+| `1.5rem` | `h2` section title |
+| `1rem` | Body, action button |
+| `0.875rem` | Table, timestamp, secondary labels, compact buttons |
+
+Font weight `600`: profit values, table headers.
+
+## Component Patterns
+
+### Filled button (`.refresh-btn`)
+- `background-color: var(--color-action)` → hover: `var(--color-action-hover)`
+- `padding: 0.75rem 1.5rem`, `border-radius: var(--radius-md)`, `font-size: 1rem`
+- `:focus-visible`: `outline: 2px solid var(--color-accent); outline-offset: 2px`
+- `:active`: `transform: scale(0.97)`
+
+### Ghost/outline button (`.sort-toggle-btn`, `.fullscreen-toggle-btn`)
+- `background: transparent`, `border: 1px solid var(--border-default)`, `color: var(--text-secondary)`
+- Hover: `border-color: var(--color-accent); color: var(--color-accent)`
+- `:focus-visible`: same accent outline ring as filled button
+- `:active`: `transform: scale(0.97)`
+
+### Section card (`.trades-section`, `.info`)
+- `background-color: var(--surface-card)`, `border: 1px solid var(--border-subtle)`, `border-radius: var(--radius-md)`, `padding: 1rem`
+
+### Section header (`.trades-header`)
+- `display: flex`, `justify-content: space-between`, `align-items: center`
+- `margin-bottom: 1rem`, `padding-bottom: 0.5rem`, `border-bottom: 1px solid var(--border-subtle)`
+- Title: `color: var(--color-accent)`
+
+## Chart-specific (JS, not CSS)
+Chart colors are LightweightCharts API options passed in `index.html` inline `<script>`.
+They are intentionally separate from the CSS token system (different rendering context).
+
+| Value | Usage |
+|---|---|
+| `#1e1e3c` | Chart layout background |
+| `#DDD` | Chart text color |
+| `#2B2B43` | Grid lines, scale borders |
+| `#26a69a` / `#ef5350` | Candlestick up/down (TradingView convention) |

Makefile

@@ -1,7 +1,7 @@
 # Makefile for Runner - PineScript Go Port
 # Centralized build automation following Go project conventions
 
-.PHONY: help build test test-unit test-integration test-e2e test-golden test-golden-update test-parser test-codegen test-runtime test-series test-syminfo regression-syminfo bench bench-series coverage coverage-show check ci clean clean-all cross-compile fmt vet lint build-strategy
+.PHONY: help build test test-unit test-integration test-e2e test-golden test-golden-update test-parser test-codegen test-runtime test-series test-syminfo regression-syminfo test-ui bench bench-series coverage coverage-show check ci clean clean-all cross-compile fmt vet lint build-strategy
 
 # Project configuration
 PROJECT_NAME := runner
@@ -161,6 +161,11 @@ test-syminfo: ## Run syminfo.tickerid integration tests only
 test-syminfo-regression: ## Run syminfo.tickerid regression test suite
 	@./scripts/test-syminfo-regression.sh
 
+test-ui: ## Run chart viewer JS unit tests (node:test, no install required)
+	@echo "Running chart viewer JS tests..."
+	@node --test out/tests/*.test.js
+	@echo "✓ Chart UI tests passed"
+
 bench: ## Run benchmarks
 	@echo "Running benchmarks..."
 	@ $(GO) test $(BENCH_FLAGS) -bench=. ./...
@@ -356,21 +361,9 @@ all: ci ## Full validation (format, vet, lint, build, all tests)
 
 install-hooks: ## Install git pre-commit hook
 	@echo "Installing pre-commit hook..."
-	@echo '#!/bin/sh' > .git/hooks/pre-commit
-	@echo '# Git pre-commit hook - full validation' >> .git/hooks/pre-commit
-	@echo 'set -e' >> .git/hooks/pre-commit
-	@echo 'export PATH="$$HOME/.local/go/bin:/usr/local/go/bin:$$PATH"' >> .git/hooks/pre-commit
-	@echo 'export GOPATH="$$HOME/go"' >> .git/hooks/pre-commit
-	@echo 'export PATH="$$PATH:$$GOPATH/bin"' >> .git/hooks/pre-commit
-	@echo 'if ! command -v go >/dev/null 2>&1; then' >> .git/hooks/pre-commit
-	@echo '    echo "✗ Go not found. Run: make install"' >> .git/hooks/pre-commit
-	@echo '    exit 1' >> .git/hooks/pre-commit
-	@echo 'fi' >> .git/hooks/pre-commit
-	@echo 'echo "🔍 Running pre-commit validation..."' >> .git/hooks/pre-commit
-	@echo 'make all' >> .git/hooks/pre-commit
-	@echo 'exit 0' >> .git/hooks/pre-commit
+	@cp scripts/pre-commit-hook.sh .git/hooks/pre-commit
 	@chmod +x .git/hooks/pre-commit
-	@echo "✓ Pre-commit hook installed (runs: make all)"
+	@echo "✓ Pre-commit hook installed"
 
 install: ## Install Go to ~/.local (no sudo required)
 	@./scripts/install-deps.sh

cmd/pine-gen/main.go

@@ -118,6 +118,8 @@ func main() {
 		os.Exit(1)
 	}
 
+	reportFeatureGaps(strategyCode.FeatureGaps)
+
 	temporaryDirectory := os.TempDir()
 
 	/* Create unique temp file to avoid conflicts when running tests in parallel */
@@ -141,6 +143,16 @@ func main() {
 	fmt.Printf("Next: Compile with: go build -o %s %s\n", *outputFlag, temporaryGoFile)
 }
 
+func reportFeatureGaps(gaps []string) {
+	if len(gaps) == 0 {
+		return
+	}
+	fmt.Fprintf(os.Stderr, "WARNING: %d unimplemented Pine function(s) — binary runs with stubs:\n", len(gaps))
+	for _, name := range gaps {
+		fmt.Fprintf(os.Stderr, "  - %s()\n", name)
+	}
+}
+
 func deriveStrategyNameFromSourceFile(inputPath string) string {
 	baseFilename := filepath.Base(inputPath)
 	extension := filepath.Ext(baseFilename)

codegen/argument_expression_generator.go

@@ -95,19 +95,22 @@ func (g *ArgumentExpressionGenerator) ensureFloat64(expr ast.Expression, code st
 }
 
 func (g *ArgumentExpressionGenerator) generateIdentifier(id *ast.Identifier) (string, error) {
+	expectsSeries := false
+	if g.signatureRegistry != nil {
+		paramType, hasSignature := g.signatureRegistry.GetParameterType(g.functionName, g.parameterIndex)
+		expectsSeries = hasSignature && paramType == ParamTypeSeries
+	}
+
 	if constVal, isConstant := g.generator.constants[id.Name]; isConstant {
 		if constVal == "input.source" {
+			if expectsSeries {
+				return fmt.Sprintf("%sSeries", id.Name), nil
+			}
 			return fmt.Sprintf("%sSeries.GetCurrent()", id.Name), nil
 		}
 		return id.Name, nil
 	}
 
-	expectsSeries := false
-	if g.signatureRegistry != nil {
-		paramType, hasSignature := g.signatureRegistry.GetParameterType(g.functionName, g.parameterIndex)
-		expectsSeries = hasSignature && paramType == ParamTypeSeries
-	}
-
 	// Arrow resolver checked before builtins; bypassed when passing to a series-typed parameter
 	// so the identifier routes to *Series by name convention instead of scalar resolution.
 	if !expectsSeries && g.generator.arrowAccessResolver != nil {

codegen/argument_extractor_test.go

@@ -142,9 +142,7 @@ func TestExtractNamedOrPositional_UseDefault(t *testing.T) {
 }
 
 func TestExtractWhenCondition_Found(t *testing.T) {
-	g := &generator{
-		builtinHandler: NewBuiltinIdentifierHandler(),
-	}
+	g := newTestGenerator()
 	extractor := &ArgumentExtractor{generator: g}
 
 	args := []ast.Expression{

codegen/argument_parser.go

@@ -157,14 +157,27 @@ func (p *ArgumentParser) ParseInt(expr ast.Expression) ParsedArgument {
 
 /*
 ParseFloat extracts a float literal from an AST expression.
-Handles both float64 and int AST literal types.
+Handles float64, int, and UnaryExpression for negative numbers.
 
 Returns:
 
 	ParsedArgument.IsValid = true if numeric literal found
 	ParsedArgument.Value = float64 value
 */
 func (p *ArgumentParser) ParseFloat(expr ast.Expression) ParsedArgument {
+	if unary, ok := expr.(*ast.UnaryExpression); ok && unary.Operator == "-" {
+		inner := p.ParseFloat(unary.Argument)
+		if inner.IsValid {
+			return ParsedArgument{
+				IsValid:    true,
+				IsLiteral:  true,
+				Value:      -inner.MustBeFloat(),
+				SourceExpr: expr,
+			}
+		}
+		return ParsedArgument{IsValid: false, SourceExpr: expr}
+	}
+
 	lit, ok := expr.(*ast.Literal)
 	if !ok {
 		return ParsedArgument{IsValid: false, SourceExpr: expr}