feat: add now line rendering to Gantt charts (RFC-0017)

Add vertical "now line" markers to Gantt chart renderers showing the
status date and/or today's date as visual reference points.

Features:
- NowLineConfig struct for configuring now line rendering
- HTML/SVG: Red solid line for status date, green dashed for today
- MermaidJS: todayMarker directive support
- PlantUML: Date coloring with status_date
- WASM Playground: Toggle checkbox (default: enabled)
- CLI flags: --as-of, --no-now-line, --show-today
- TJP parser: Handle `now` attribute -> project.status_date
- MS Project import: Extract status_date from project properties

Tests: 10 unit tests, 5 WASM tests, 6 E2E tests

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: 2 people

CLAUDE.md

@@ -21,7 +21,7 @@ This project follows **Semantic Versioning** (SemVer):
 
 Version is set in `Cargo.toml` under `[workspace.package]`:
 ```toml
-version = "0.12.2"
+version = "0.13.0"
 ```
 
 All crates inherit this version via `version.workspace = true`.

Cargo.lock

@@ -14,7 +14,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.12.2"
+version = "0.13.0"
 edition = "2021"
 rust-version = "1.75"
 license = "MIT OR Apache-2.0"
@@ -24,10 +24,10 @@ categories = ["command-line-utilities", "development-tools"]
 
 [workspace.dependencies]
 # Internal crates (version required for crates.io publishing)
-utf8proj-core = { version = "0.12.0", path = "crates/utf8proj-core" }
-utf8proj-parser = { version = "0.12.0", path = "crates/utf8proj-parser" }
-utf8proj-solver = { version = "0.12.0", path = "crates/utf8proj-solver" }
-utf8proj-render = { version = "0.12.0", path = "crates/utf8proj-render" }
+utf8proj-core = { version = "0.13.0", path = "crates/utf8proj-core" }
+utf8proj-parser = { version = "0.13.0", path = "crates/utf8proj-parser" }
+utf8proj-solver = { version = "0.13.0", path = "crates/utf8proj-solver" }
+utf8proj-render = { version = "0.13.0", path = "crates/utf8proj-render" }
 
 # Date/Time
 chrono = { version = "0.4", features = ["serde"] }

Cargo.toml

@@ -204,6 +204,19 @@ enum Commands {
         /// Number of days to show in daily Excel schedule (default: 60)
         #[arg(long, default_value = "60")]
         days: u32,
+
+        /// Status date for now line (RFC-0017). Format: YYYY-MM-DD.
+        /// Defaults to project.status_date or today if not specified.
+        #[arg(long, value_name = "DATE")]
+        as_of: Option<String>,
+
+        /// Disable now line rendering on Gantt chart (RFC-0017)
+        #[arg(long)]
+        no_now_line: bool,
+
+        /// Show today line separately when status_date differs from today (RFC-0017)
+        #[arg(long)]
+        show_today: bool,
     },
 
     /// Run performance benchmarks
@@ -455,6 +468,9 @@ fn main() -> Result<()> {
             context_depth,
             daily,
             days,
+            as_of,
+            no_now_line,
+            show_today,
         }) => cmd_gantt(
             &file,
             &output,
@@ -470,6 +486,9 @@ fn main() -> Result<()> {
             context_depth,
             daily,
             days,
+            as_of.as_deref(),
+            no_now_line,
+            show_today,
         ),
         Some(Commands::Benchmark {
             topology,
@@ -1040,6 +1059,9 @@ fn cmd_gantt(
     context_depth: usize,
     daily: bool,
     days: u32,
+    as_of: Option<&str>,
+    no_now_line: bool,
+    show_today: bool,
 ) -> Result<()> {
     use utf8proj_render::DisplayMode;
     // Parse the file
@@ -1175,8 +1197,8 @@ fn cmd_gantt(
                 .with_context(|| "Failed to render SVG Gantt chart")?
         }
         "html" => {
-            // HTML format with focus view support
-            use utf8proj_render::gantt::{FocusConfig, HtmlGanttRenderer};
+            // HTML format with focus view and now line support
+            use utf8proj_render::gantt::{FocusConfig, HtmlGanttRenderer, NowLineConfig};
 
             let mut renderer = HtmlGanttRenderer::new();
             renderer.label_width = width as u32;
@@ -1198,6 +1220,27 @@ fn cmd_gantt(
                 }
             }
 
+            // Configure now line (RFC-0017)
+            if no_now_line {
+                renderer.now_line = NowLineConfig::disabled();
+            } else {
+                // Resolve status date: --as-of > project.status_date > today
+                let status_date = if let Some(date_str) = as_of {
+                    chrono::NaiveDate::parse_from_str(date_str, "%Y-%m-%d")
+                        .with_context(|| format!("Invalid date format '{}', expected YYYY-MM-DD", date_str))?
+                } else if let Some(date) = project.status_date {
+                    date
+                } else {
+                    chrono::Local::now().date_naive()
+                };
+
+                let mut now_line_config = NowLineConfig::with_status_date(status_date);
+                if show_today {
+                    now_line_config = now_line_config.with_today();
+                }
+                renderer.now_line = now_line_config;
+            }
+
             renderer
                 .render(&project, &schedule)
                 .with_context(|| "Failed to render HTML Gantt chart")?

crates/utf8proj-cli/src/main.rs

@@ -113,6 +113,13 @@ fn parse_project_decl(
                 Rule::workinghours_attr => {
                     // Could configure calendar
                 }
+                Rule::now_attr => {
+                    // RFC-0017: Parse 'now' attribute as status_date
+                    let mut inner = actual_attr.into_inner();
+                    if let Some(date_pair) = inner.next() {
+                        project.status_date = Some(parse_date(date_pair.as_str())?);
+                    }
+                }
                 _ => {}
             }
         }
@@ -690,4 +697,22 @@ mod tests {
             utf8proj_core::DependencyType::FinishToFinish
         );
     }
+
+    #[test]
+    fn parse_project_now_attribute() {
+        // RFC-0017: 'now' attribute sets status_date
+        let input = r#"
+            project test "Test" 2025-01-01 - 2025-12-31 {
+                now 2025-03-15
+            }
+            task t1 "Task 1" { duration 5d }
+        "#;
+
+        let project = parse(input).unwrap();
+        assert!(project.status_date.is_some(), "status_date should be set from 'now'");
+        assert_eq!(
+            project.status_date.unwrap(),
+            chrono::NaiveDate::from_ymd_opt(2025, 3, 15).unwrap()
+        );
+    }
 }