fix(mermaid): switch to crates.io and patch dagre_rust panic

Switch mermaid-rs-renderer from git dependency to crates.io 0.1.

Vendor and patch dagre_rust 0.0.5 to fix upstream panic in
remove_edge_label_proxies() where unwrap() is called on None
when processing edge label proxies without edge references.

This enables sequence diagrams and state diagrams that previously
crashed the build.

patches/dagre_rust/src/lib.rs

@@ -0,0 +1,131 @@
+pub mod layout;
+
+use crate::layout::add_border_segments::BorderTypeName;
+use graphlib_rust::Edge;
+use ordered_hashmap::OrderedHashMap;
+
+#[allow(dead_code)]
+#[derive(Debug, Clone, Default)]
+pub struct GraphNode {
+    pub x: f32,
+    pub y: f32,
+    pub width: f32,
+    pub height: f32,
+    pub class: Option<String>,
+    pub label: Option<GraphEdge>,
+    pub padding: Option<f32>,
+    pub padding_x: Option<f32>,
+    pub padding_y: Option<f32>,
+    pub rx: Option<f32>,
+    pub ry: Option<f32>,
+    pub shape: Option<String>,
+    pub dummy: Option<String>,
+    pub rank: Option<i32>,
+    pub min_rank: Option<i32>,
+    pub max_rank: Option<i32>,
+    pub order: Option<usize>,
+    pub border_top: Option<String>,
+    pub border_bottom: Option<String>,
+    pub border_left: Option<OrderedHashMap<i32, String>>,
+    pub border_right: Option<OrderedHashMap<i32, String>>,
+    pub border_left_: Option<String>,
+    pub border_right_: Option<String>,
+    pub low: Option<usize>,
+    pub lim: Option<usize>,
+    pub parent: Option<String>,
+    pub e: Option<Edge>,
+    pub edge_label: Option<GraphEdge>,
+    pub edge_obj: Option<Edge>,
+    pub labelpos: Option<String>,
+    pub border_type: Option<BorderTypeName>,
+    pub self_edges: Vec<(Edge, GraphEdge)>,
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct GraphEdgePoint {
+    pub x: f32,
+    pub y: f32,
+}
+
+#[allow(dead_code)]
+#[derive(Debug, Clone)]
+pub struct GraphEdge {
+    pub forward_name: Option<String>,
+    pub reversed: Option<bool>,
+    pub minlen: Option<f32>,
+    pub weight: Option<f32>,
+    pub width: Option<f32>,
+    pub height: Option<f32>,
+    pub label_rank: Option<i32>,
+    pub labeloffset: Option<f32>,
+    pub labelpos: Option<String>,
+    pub nesting_edge: Option<bool>,
+    pub cutvalue: Option<f32>,
+    pub points: Option<Vec<GraphEdgePoint>>,
+    pub x: f32,
+    pub y: f32,
+}
+
+#[allow(dead_code)]
+#[derive(Debug, Clone)]
+pub struct GraphConfig {
+    pub width: f32,
+    pub height: f32,
+
+    pub nodesep: Option<f32>,      // default 50
+    pub edgesep: Option<f32>,      // default 20
+    pub ranksep: Option<f32>,      // default 50
+    pub marginx: Option<f32>,      // default 0
+    pub marginy: Option<f32>,      // default 0
+    pub rankdir: Option<String>,   // lr, lr, tb, bt // default tb
+    pub acyclicer: Option<String>, // greedy, dfs, unknown-should-still-work
+    pub ranker: Option<String>, // "longest-path", "tight-tree", "network-simplex", "unknown-should-still-work"
+    pub align: Option<String>,
+    pub nesting_root: Option<String>, // id of dummy nesting root
+    pub root: Option<String>,
+    pub node_rank_factor: Option<f32>, // default 0
+    pub dummy_chains: Option<Vec<String>>,
+}
+
+impl Default for GraphConfig {
+    fn default() -> Self {
+        Self {
+            width: 0.0,
+            height: 0.0,
+            nodesep: Some(50.0),
+            edgesep: Some(20.0),
+            ranksep: Some(50.0),
+            marginx: None,
+            marginy: None,
+            rankdir: Some("tb".to_string()),
+            acyclicer: None,
+            ranker: None,
+            align: None,
+            nesting_root: None,
+            root: None,
+            node_rank_factor: None,
+            dummy_chains: None,
+        }
+    }
+}
+
+impl Default for GraphEdge {
+    fn default() -> Self {
+        Self {
+            forward_name: None,
+            reversed: None,
+            minlen: Some(1.0),
+            weight: Some(1.0),
+            width: Some(0.0),
+            height: Some(0.0),
+            label_rank: None,
+            labeloffset: Some(0.0),
+            labelpos: Some("r".to_string()),
+            nesting_edge: None,
+            cutvalue: None,
+            points: None,
+            x: 0.0,
+            y: 0.0,
+        }
+    }
+}