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/Cargo.toml

@@ -0,0 +1,28 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+authors     = ["Ameer Hamza <r3alst@gmail.com>"]
+categories  = ["graph", "dagre"]
+description = "Dagre implementation in Rust"
+edition     = "2021"
+keywords    = ["dagre", "graph", "dag"]
+license     = "Apache-2.0"
+name        = "dagre_rust"
+readme      = "README.md"
+repository  = "https://github.com/r3alst/dagre-rust"
+version     = "0.0.5"
+
+[dependencies.graphlib_rust]
+version = "0.0.2"
+
+[dependencies.ordered_hashmap]
+version = "0.0.3"