refactor: render the shell in the client (#3487)

* feat: add opt-in client-rendered shell

* feat: add client-owned shell mouse controls

* feat: complete client-owned shell chrome

* feat: add client-owned shell settings and notifications

* feat: run client shell custom commands

* feat: render popup terminals in client shell

* feat: add client-owned scrollback and copy mode

* fix: preserve client worktree trust defaults

* feat: render startup diagnostics in client shell

* feat: render onboarding in client shell

* feat: render product announcements in client shell

* feat: render release notes in client shell

* feat: render mobile switcher in client shell

* feat: render kitty graphics in client shell

* fix: preserve client shell lifecycle coherence

* refactor: route client shell commands through endpoint connections

* refactor: make the client-rendered shell the default

* refactor: remove monolithic launch mode

* refactor: complete client-rendered shell cutover

* perf: retain client pane surface updates

* perf: scale retained pane surface updates

* perf: remove remote pane input latency

* test: make client shell checks platform-independent

* fix: prevent client timer starvation

* test: fix client shell platform gates

* test: accept retained surfaces in cross-area checks

* test: make client mode assertions platform-neutral

* fix: badge only outdated integrations

3 files changed, 94 insertions, 10 deletions

diff --git a/src/config/keybinds.rs b/src/config/keybinds.rs
index 6cddd3ac..bec1af66 100644
--- a/src/config/keybinds.rs
+++ b/src/config/keybinds.rs
@@ -169,6 +169,18 @@ pub struct ActionKeybinds {
 }
 
 impl ActionKeybinds {
+    pub(crate) fn from_labels(labels: &[String]) -> Result<Self, String> {
+        let mut bindings = Vec::new();
+        for label in labels {
+            match parse_binding_string(label) {
+                Some(ParsedBinding::Single(binding)) => bindings.push(binding),
+                Some(ParsedBinding::Range(range)) => bindings.extend(range),
+                None => return Err(format!("invalid endpoint command binding: {label}")),
+            }
+        }
+        Ok(Self { bindings })
+    }
+
     #[cfg(test)]
     pub fn prefix(label: &str) -> Self {
         let raw = if label.starts_with("prefix+") {
diff --git a/src/config/model.rs b/src/config/model.rs
index c10cd733..552c19de 100644
--- a/src/config/model.rs
+++ b/src/config/model.rs
@@ -101,15 +101,6 @@ pub enum AgentPanelSortConfig {
     Priority,
 }
 
-impl AgentPanelSortConfig {
-    pub fn as_str(self) -> &'static str {
-        match self {
-            Self::Spaces => "spaces",
-            Self::Priority => "priority",
-        }
-    }
-}
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Deserialize)]
 #[serde(rename_all = "lowercase")]
 enum LegacyAgentPanelScopeConfig {
@@ -372,7 +363,7 @@ pub struct KeysConfig {
     pub navigate_pane_up: BindingConfig,
     /// Focus the pane to the right in navigate mode. Default: "l". Right arrow is always an alias.
     pub navigate_pane_right: BindingConfig,
-    /// Detach from server/client mode, or exit --no-session mode. Default: "prefix+q".
+    /// Detach the current client from its Herdr server. Default: "prefix+q".
     pub detach: BindingConfig,
     /// Reload config.toml in the running app/server. Default: "prefix+shift+r".
     pub reload_config: BindingConfig,
@@ -593,6 +584,12 @@ pub(crate) struct KeysConfigOverlay {
     command: Option<Vec<CommandKeybindConfig>>,
 }
 
+impl KeysConfigOverlay {
+    pub(crate) fn set_prefix(&mut self, prefix: String) {
+        self.prefix = Some(prefix);
+    }
+}
+
 impl<'de> Deserialize<'de> for KeysConfig {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where
diff --git a/src/config/write.rs b/src/config/write.rs
new file mode 100644
index 00000000..75244583
--- /dev/null
+++ b/src/config/write.rs
@@ -0,0 +1,75 @@
+#[derive(Clone, Copy)]
+pub(crate) enum ConfigEdit<'a> {
+    Theme(&'a str),
+    StatusIndicators(super::StatusIndicatorStyle),
+    Sound(bool),
+    ToastDelivery(super::ToastDelivery),
+}
+
+impl ConfigEdit<'_> {
+    pub(crate) fn description(self) -> &'static str {
+        match self {
+            Self::Theme(_) => "theme",
+            Self::StatusIndicators(_) => "status indicators",
+            Self::Sound(_) => "sound setting",
+            Self::ToastDelivery(_) => "toast setting",
+        }
+    }
+
+    pub(crate) fn apply(self, content: &str) -> String {
+        match self {
+            Self::Theme(name) => {
+                let content =
+                    super::upsert_section_value(content, "theme", "name", &format!("\"{name}\""));
+                super::upsert_section_bool(&content, "theme", "auto_switch", false)
+            }
+            Self::StatusIndicators(style) => super::upsert_section_value(
+                content,
+                "ui",
+                "status_indicators",
+                &format!("\"{}\"", style.as_str()),
+            ),
+            Self::Sound(enabled) => {
+                super::upsert_section_bool(content, "ui.sound", "enabled", enabled)
+            }
+            Self::ToastDelivery(delivery) => {
+                let value = match delivery {
+                    super::ToastDelivery::Off => "\"off\"",
+                    super::ToastDelivery::Herdr => "\"herdr\"",
+                    super::ToastDelivery::Terminal => "\"terminal\"",
+                    super::ToastDelivery::System => "\"system\"",
+                };
+                let content = super::upsert_section_value(content, "ui.toast", "delivery", value);
+                super::remove_section_key(&content, "ui.toast", "enabled")
+            }
+        }
+    }
+}
+
+pub(crate) fn update_file_at(
+    path: &std::path::Path,
+    description: &str,
+    update: impl FnOnce(&str) -> String,
+) -> Result<(), String> {
+    if let Some(parent) = path.parent() {
+        std::fs::create_dir_all(parent)
+            .map_err(|error| format!("failed to create config directory: {error}"))?;
+    }
+    let content = match std::fs::read_to_string(path) {
+        Ok(content) => content,
+        Err(error) if error.kind() == std::io::ErrorKind::NotFound => String::new(),
+        Err(error) => {
+            return Err(format!(
+                "failed to read config before saving {description}: {error}"
+            ));
+        }
+    };
+    std::fs::write(path, update(&content))
+        .map_err(|error| format!("failed to save {description}: {error}"))
+}
+
+pub(crate) fn write_edit(edit: ConfigEdit<'_>) -> Result<(), String> {
+    update_file_at(&super::config_path(), edit.description(), |content| {
+        edit.apply(content)
+    })
+}