simplify: dedupe render_resolve_errors across crates

Three byte-identical copies of `render_resolve_errors` had drifted into
`fabro-server/src/run_manifest.rs`, `fabro-workflow/src/operations/start.rs`,
and `fabro-workflow/src/operations/create.rs`. Each one folded a
`&[ResolveError]` into a semicolon-separated string for surfacing through
`anyhow!` / `Error::Precondition` envelopes.

Promote the helper to `fabro_config::render_resolve_errors` (it lives next
to `ResolveError`, the type it acts on) and rewrite the four call sites
in workflow ops plus the one in run_manifest to call the shared version.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lib/crates/fabro-config/src/lib.rs

@@ -37,10 +37,10 @@ pub use load::{
 };
 pub use parse::{ParseError, parse_settings_layer};
 pub use resolve::{
-    ResolveError, dev_token_auth_enabled, resolve_cli, resolve_cli_from_file, resolve_features,
-    resolve_features_from_file, resolve_project, resolve_project_from_file, resolve_run,
-    resolve_run_from_file, resolve_server, resolve_server_from_file, resolve_storage_root,
-    resolve_workflow, resolve_workflow_from_file,
+    ResolveError, dev_token_auth_enabled, render_resolve_errors, resolve_cli,
+    resolve_cli_from_file, resolve_features, resolve_features_from_file, resolve_project,
+    resolve_project_from_file, resolve_run, resolve_run_from_file, resolve_server,
+    resolve_server_from_file, resolve_storage_root, resolve_workflow, resolve_workflow_from_file,
 };
 use serde::de::DeserializeOwned;
 pub use storage::{RunScratch, RuntimeDirectory, Storage};

lib/crates/fabro-config/src/resolve/mod.rs

@@ -100,6 +100,17 @@ pub fn resolve_workflow_from_file(
     }
 }
 
+/// Render a list of [`ResolveError`]s as a single semicolon-separated message
+/// suitable for surfacing through `anyhow!` / `Error::Precondition` / similar
+/// human-facing error envelopes.
+pub fn render_resolve_errors(errors: &[ResolveError]) -> String {
+    errors
+        .iter()
+        .map(ToString::to_string)
+        .collect::<Vec<_>>()
+        .join("; ")
+}
+
 pub(crate) fn require_interp(
     value: Option<&InterpString>,
     path: &str,

lib/crates/fabro-server/src/run_manifest.rs

@@ -361,7 +361,7 @@ async fn build_preflight_report(
         &configured_providers,
     );
     let resolved_run = fabro_config::resolve_run_from_file(&materialized)
-        .map_err(|errors| anyhow!(render_resolve_errors(&errors)))?;
+        .map_err(|errors| anyhow!(fabro_config::render_resolve_errors(&errors)))?;
     let server_settings = state.server_settings();
     let github_integration = &server_settings.server.integrations.github;
     let sandbox_provider = resolve_sandbox_provider(&resolved_run)?;
@@ -701,14 +701,6 @@ fn resolve_model_provider(
     }
 }
 
-fn render_resolve_errors(errors: &[fabro_config::ResolveError]) -> String {
-    errors
-        .iter()
-        .map(ToString::to_string)
-        .collect::<Vec<_>>()
-        .join("; ")
-}
-
 fn runtime_daytona_config(settings: &DaytonaSettings) -> DaytonaConfig {
     DaytonaConfig {
         auto_stop_interval: settings.auto_stop_interval,

lib/crates/fabro-workflow/src/operations/create.rs

@@ -284,23 +284,15 @@ fn store_error(err: impl std::fmt::Display) -> Error {
     Error::engine(err.to_string())
 }
 
-fn render_resolve_errors(errors: &[fabro_config::ResolveError]) -> String {
-    errors
-        .iter()
-        .map(ToString::to_string)
-        .collect::<Vec<_>>()
-        .join("; ")
-}
-
 fn resolve_settings_tree(settings: &SettingsLayer) -> Result<ResolvedSettingsTree, Error> {
     Ok(ResolvedSettingsTree {
         server_storage_root: fabro_config::resolve_storage_root(settings),
         project:             fabro_config::resolve_project_from_file(settings)
-            .map_err(|errors| Error::Precondition(render_resolve_errors(&errors)))?,
+            .map_err(|errors| Error::Precondition(fabro_config::render_resolve_errors(&errors)))?,
         workflow:            fabro_config::resolve_workflow_from_file(settings)
-            .map_err(|errors| Error::Precondition(render_resolve_errors(&errors)))?,
+            .map_err(|errors| Error::Precondition(fabro_config::render_resolve_errors(&errors)))?,
         run:                 fabro_config::resolve_run_from_file(settings)
-            .map_err(|errors| Error::Precondition(render_resolve_errors(&errors)))?,
+            .map_err(|errors| Error::Precondition(fabro_config::render_resolve_errors(&errors)))?,
     })
 }
 
@@ -313,7 +305,7 @@ fn combined_labels(settings: &ResolvedSettingsTree) -> HashMap<String, String> {
 
 fn validate_sandbox_provider(settings: &SettingsLayer) -> Result<(), Error> {
     let resolved = fabro_config::resolve_run_from_file(settings)
-        .map_err(|errors| Error::Precondition(render_resolve_errors(&errors)))?;
+        .map_err(|errors| Error::Precondition(fabro_config::render_resolve_errors(&errors)))?;
     resolved
         .sandbox
         .provider

lib/crates/fabro-workflow/src/operations/start.rs

@@ -310,7 +310,7 @@ impl RunSession {
             .map_or((None, None), |(url, branch)| (Some(url), branch));
 
         let resolved = fabro_config::resolve_run_from_file(settings)
-            .map_err(|errors| Error::Precondition(render_resolve_errors(&errors)))?;
+            .map_err(|errors| Error::Precondition(fabro_config::render_resolve_errors(&errors)))?;
 
         let sandbox_provider = resolve_sandbox_provider(&resolved)?;
         let sandbox_provider =
@@ -518,14 +518,6 @@ fn resolve_fallback_chain(
     Catalog::builtin().build_fallback_chain(provider, model, &by_provider)
 }
 
-fn render_resolve_errors(errors: &[fabro_config::ResolveError]) -> String {
-    errors
-        .iter()
-        .map(ToString::to_string)
-        .collect::<Vec<_>>()
-        .join("; ")
-}
-
 fn runtime_mcp_server(settings: &ResolvedMcpServerSettings) -> McpServerSettings {
     McpServerSettings {
         name:                 settings.name.clone(),