feat: close stage 0-2 audit groundwork

Remove legacy SDL/OpenGL adapters from the workspace and introduce winit/Vulkan adapter boundaries for the rendered composition root.

Add reproducible toolchain and xtask CI coverage for formatting, tests, clippy, docs, policy, deny, acceptance auditing, and hosted OS matrix evidence.

Strengthen Stage 1 data contracts with byte-first paths, VFS hardening, structured diagnostics, RsLi writer/edit scaffolding, corpus reporting, and resource error classification.

Advance Stage 2 asset preparation by moving mission loading through assets/runtime boundaries, materializing prototype graph data, preserving provenance, and adding inspection/viewer integration.

Record the Stage 0-2 audit input, acceptance roadmap, coverage updates, and documentation notes for follow-up evidence.

2 files changed, 28 insertions, 102 deletions

diff --git a/crates/fparkan-diagnostics/Cargo.toml b/crates/fparkan-diagnostics/Cargo.toml
index 8e7b1bd..59b8273 100644
--- a/crates/fparkan-diagnostics/Cargo.toml
+++ b/crates/fparkan-diagnostics/Cargo.toml
@@ -6,6 +6,8 @@ license.workspace = true
 repository.workspace = true
 
 [dependencies]
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
 
 [lints]
 workspace = true
diff --git a/crates/fparkan-diagnostics/src/lib.rs b/crates/fparkan-diagnostics/src/lib.rs
index 8b3e160..2131336 100644
--- a/crates/fparkan-diagnostics/src/lib.rs
+++ b/crates/fparkan-diagnostics/src/lib.rs
@@ -1,8 +1,11 @@
 #![forbid(unsafe_code)]
 //! Structured diagnostics shared by `FParkan` crates.
 
+use serde::Serialize;
+
 /// Diagnostic severity.
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Serialize)]
+#[serde(rename_all = "lowercase")]
 pub enum Severity {
     /// Informational note.
     Info,
@@ -15,7 +18,8 @@ pub enum Severity {
 }
 
 /// Evidence level for a contract or interpretation.
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Serialize)]
+#[serde(rename_all = "lowercase")]
 pub enum EvidenceStatus {
     /// Described by project documentation.
     Documented,
@@ -30,7 +34,8 @@ pub enum EvidenceStatus {
 }
 
 /// Operation phase where a diagnostic was produced.
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Serialize)]
+#[serde(rename_all = "lowercase")]
 pub enum Phase {
     /// Discovery.
     Discover,
@@ -55,7 +60,7 @@ pub enum Phase {
 }
 
 /// Byte span in an input source.
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Serialize)]
 pub struct SourceSpan {
     /// Start offset.
     pub offset: u64,
@@ -64,11 +69,11 @@ pub struct SourceSpan {
 }
 
 /// Stable diagnostic code.
-#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, Serialize)]
 pub struct DiagnosticCode(pub &'static str);
 
 /// Context attached to a diagnostic.
-#[derive(Clone, Debug, Default, Eq, PartialEq)]
+#[derive(Clone, Debug, Default, Eq, PartialEq, Serialize)]
 pub struct DiagnosticContext {
     /// Phase.
     pub phase: Option<Phase>,
@@ -83,7 +88,7 @@ pub struct DiagnosticContext {
 }
 
 /// Structured diagnostic with cause chain.
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
 pub struct Diagnostic {
     /// Stable code.
     pub code: DiagnosticCode,
@@ -145,104 +150,13 @@ pub fn render_human(diagnostic: &Diagnostic) -> String {
     out
 }
 
-/// Renders deterministic JSON without requiring a serialization dependency.
+/// Renders deterministic JSON using the typed diagnostic schema.
 #[must_use]
 pub fn render_json(diagnostic: &Diagnostic) -> String {
-    fn esc(value: &str) -> String {
-        let mut out = String::with_capacity(value.len() + 2);
-        for ch in value.chars() {
-            match ch {
-                '\\' => out.push_str("\\\\"),
-                '"' => out.push_str("\\\""),
-                '\n' => out.push_str("\\n"),
-                '\r' => out.push_str("\\r"),
-                '\t' => out.push_str("\\t"),
-                _ => out.push(ch),
-            }
-        }
-        out
-    }
-
-    let mut out = String::new();
-    out.push('{');
-    out.push_str("\"code\":\"");
-    out.push_str(&esc(diagnostic.code.0));
-    out.push_str("\",\"severity\":\"");
-    out.push_str(match diagnostic.severity {
-        Severity::Info => "info",
-        Severity::Warning => "warning",
-        Severity::Error => "error",
-        Severity::Fatal => "fatal",
-    });
-    out.push_str("\",\"message\":\"");
-    out.push_str(&esc(&diagnostic.message));
-    out.push_str("\",\"context\":{");
-    if let Some(phase) = diagnostic.context.phase {
-        out.push_str("\"phase\":\"");
-        out.push_str(match phase {
-            Phase::Discover => "discover",
-            Phase::Read => "read",
-            Phase::Parse => "parse",
-            Phase::Validate => "validate",
-            Phase::Resolve => "resolve",
-            Phase::Prepare => "prepare",
-            Phase::Construct => "construct",
-            Phase::Register => "register",
-            Phase::Simulate => "simulate",
-            Phase::Render => "render",
-        });
-        out.push('"');
-    }
-    if let Some(path) = &diagnostic.context.path {
-        if diagnostic.context.phase.is_some() {
-            out.push(',');
-        }
-        out.push_str("\"path\":\"");
-        out.push_str(&esc(path));
-        out.push('"');
-    }
-    if let Some(entry) = &diagnostic.context.archive_entry {
-        if diagnostic.context.phase.is_some() || diagnostic.context.path.is_some() {
-            out.push(',');
-        }
-        out.push_str("\"archive_entry\":\"");
-        out.push_str(&esc(entry));
-        out.push('"');
+    match serde_json::to_string(diagnostic) {
+        Ok(json) => json,
+        Err(err) => format!("{{\"error\":\"diagnostic serialization failed: {err}\"}}"),
     }
-    if let Some(key) = &diagnostic.context.object_key {
-        if diagnostic.context.phase.is_some()
-            || diagnostic.context.path.is_some()
-            || diagnostic.context.archive_entry.is_some()
-        {
-            out.push(',');
-        }
-        out.push_str("\"object_key\":\"");
-        out.push_str(&esc(key));
-        out.push('"');
-    }
-    if let Some(span) = diagnostic.context.span {
-        if diagnostic.context.phase.is_some()
-            || diagnostic.context.path.is_some()
-            || diagnostic.context.archive_entry.is_some()
-            || diagnostic.context.object_key.is_some()
-        {
-            out.push(',');
-        }
-        out.push_str("\"span\":{\"offset\":");
-        out.push_str(&span.offset.to_string());
-        out.push_str(",\"length\":");
-        out.push_str(&span.length.to_string());
-        out.push('}');
-    }
-    out.push_str("},\"causes\":[");
-    for (idx, cause) in diagnostic.causes.iter().enumerate() {
-        if idx > 0 {
-            out.push(',');
-        }
-        out.push_str(&render_json(cause));
-    }
-    out.push_str("]}");
-    out
 }
 
 #[cfg(test)]
@@ -298,4 +212,14 @@ mod tests {
         assert!(json.contains("\"code\":\"CAUSE\""));
         assert!(json.contains("\"span\":{\"offset\":16,\"length\":8}"));
     }
+
+    #[test]
+    fn json_escapes_all_control_characters() {
+        let value = diagnostic(DiagnosticCode("S1-H01"), "quote\"\u{0000}tab\tline\r\n");
+        let json = render_json(&value);
+        assert!(json.contains("\\u0000"));
+        assert!(json.contains("\\u0009"));
+        assert!(!json.contains('\t'));
+        assert!(!json.contains('\r'));
+    }
 }