feat(rust): write the recommended PopupNotifications banner (runicnpc 9e, D327, D328)

install and update write PopupNotifications.json into the framework's config
directory, as a banner across the top of the screen, only where the file is
missing or every setting is still PopupNotifications 0.2.1's own default (the
Version aside, numbers compared as numbers). A config with any setting
changed, or one that does not parse, is kept whole. The file carries the
plugin's Version, because PopupNotifications resets a config without one to
its defaults on load. The plan prints a "popup look" row naming the case.

Run against two scratch roots (a temporary local bypass of the RunicNPC check,
since no published bundle carries RunicNPC yet): Oxide with no config got the
banner; Carbon at the rig's defaults got the walk's banner file exactly; on
update a hand-changed config and an existing banner were both kept.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E14m6SuuY6i1vASFeGDBeY

src/rustgame/install.rs

@@ -20,6 +20,7 @@ use anyhow::{bail, Context, Result};
 
 use super::npc;
 use super::plugin::{self, ConfigView};
+use super::popup;
 use super::record::{ComponentRecord, DeployedFile, Instance, NpcRecord, RustRecord, SCHEMA};
 use super::server::{self, RustServer};
 use super::sidecar;
@@ -49,6 +50,8 @@ struct Planned {
     retired_helpers: Vec<String>,
     /// RunicNPC, when the bundle carries it (D224): absent, identical or replaced.
     npc_action: Option<BinaryAction>,
+    /// PopupNotifications' config: the banner where it is missing or the plugin's defaults (D327).
+    popup: popup::State,
     game_port: u16,
     web_port: u16,
     config_path: PathBuf,
@@ -395,6 +398,7 @@ pub fn deploy(cli: &Cli, mode: Mode) -> Result<()> {
                                 || p.npc_action.is_some_and(|a| a.writes())
                                 || p.helper_actions.iter().any(|a| a.writes())
                                 || !p.retired_helpers.is_empty()
+                                || p.popup.writes()
                         })
                         .count();
                     if restored == 0 && !binary_action.writes() {
@@ -537,10 +541,12 @@ fn plan_instance(
                 Ok(_) => BinaryAction::Replace,
             },
         );
+    let popup = popup::inspect(&server.framework.config_dir(&server.path).join(popup::FILE));
     let config_path = layout.rust_config(id);
     Ok(Planned {
         id: id.to_string(),
         running: server::is_running(&server.path),
+        popup,
         config_exists: config_path.exists(),
         config_path,
         db_path: layout.rust_db(id),
@@ -641,6 +647,18 @@ fn print_plan(
                 if p.config_exists { "kept" } else { "written" }
             ),
         );
+        ui::row(
+            "popup look",
+            &format!(
+                "{}   {}",
+                p.server
+                    .framework
+                    .config_dir(&p.server.path)
+                    .join(popup::FILE)
+                    .display(),
+                p.popup.label()
+            ),
+        );
         ui::row(
             "ports",
             &format!(
@@ -703,6 +721,26 @@ fn deploy_instance(
         ui::ok(&format!("wrote {}", plugin_config_path.display()));
     }
 
+    // PopupNotifications' look (D327): the banner, only over nothing or over the plugin's own
+    // defaults. Before the plugins, so a PopupNotifications that loads after them reads it; one
+    // already loaded keeps its old look until it is reloaded.
+    if let Some(banner) = popup::banner_for(plan.popup) {
+        let dir = plan.server.framework.config_dir(&plan.server.path);
+        std::fs::create_dir_all(&dir)
+            .with_context(|| format!("cannot create {}", dir.display()))?;
+        let path = dir.join(popup::FILE);
+        write_atomic(&path, banner.as_bytes())?;
+        ui::ok(&format!(
+            "wrote the PopupNotifications banner   {}{}",
+            path.display(),
+            if plan.running {
+                " (takes effect when PopupNotifications next loads)"
+            } else {
+                ""
+            }
+        ));
+    }
+
     // The sidecar's config, once; the token is the sidecar's to generate.
     if !plan.config_exists {
         if let Some(parent) = plan.config_path.parent() {

src/rustgame/mod.rs

@@ -15,6 +15,7 @@ mod doctor;
 mod install;
 mod npc;
 mod plugin;
+mod popup;
 mod record;
 mod server;
 mod sidecar;

src/rustgame/popup.rs

@@ -0,0 +1,312 @@
+//! The recommended PopupNotifications look: a banner across the top of the screen (docs/runicnpc/
+//! PLAN.md stage 9e, D327).
+//!
+//! PopupNotifications is optional and the operator's to install (D141); its config is the
+//! operator's too. The installer writes the banner into it only where it is **missing** or **still
+//! exactly the plugin's own defaults** — every setting equal to 0.2.1's, the `Version` aside (D328).
+//! A config with any one setting changed is somebody's choice and is kept whole, never merged into.
+//! A config that does not parse is kept too: it is not ours to repair.
+//!
+//! The file carries a `Version`: PopupNotifications resets a config whose version is missing or
+//! below 0.2.0 to its defaults on load, which would undo the banner at the first boot.
+
+use std::path::Path;
+
+use serde_json::Value;
+
+/// The config's file name, in the framework's config directory beside the bridge's.
+pub const FILE: &str = "PopupNotifications.json";
+
+/// What is there now, and so what happens to it.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum State {
+    /// No config: the banner is written, and PopupNotifications reads it when it is installed.
+    Missing,
+    /// The plugin's own defaults, untouched: the banner replaces them. Holds the file's version.
+    Defaults(Version),
+    /// Changed by someone, or unreadable: kept.
+    Theirs,
+}
+
+/// PopupNotifications' `VersionNumber`, as its config writes it.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct Version {
+    pub major: u64,
+    pub minor: u64,
+    pub patch: u64,
+}
+
+/// The version written into a config made from nothing: the release the defaults are read from.
+const WRITTEN_VERSION: Version = Version {
+    major: 0,
+    minor: 2,
+    patch: 1,
+};
+
+impl State {
+    pub fn writes(self) -> bool {
+        !matches!(self, Self::Theirs)
+    }
+
+    pub fn label(self) -> &'static str {
+        match self {
+            Self::Missing => "banner written (no config yet)",
+            Self::Defaults(_) => "banner written (was the plugin's defaults)",
+            Self::Theirs => "kept (not the plugin's defaults)",
+        }
+    }
+}
+
+/// Reads the config at `path` and says what it is.
+pub fn inspect(path: &Path) -> State {
+    match std::fs::read(path) {
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => State::Missing,
+        Err(_) => State::Theirs,
+        Ok(bytes) => classify(&bytes),
+    }
+}
+
+fn classify(bytes: &[u8]) -> State {
+    let Ok(Value::Object(mut found)) = serde_json::from_slice::<Value>(bytes) else {
+        return State::Theirs;
+    };
+    let version = found.remove("Version");
+    let Ok(Value::Object(mut defaults)) = serde_json::from_str::<Value>(&render(DEFAULTS, None))
+    else {
+        unreachable!("the defaults are valid JSON")
+    };
+    defaults.remove("Version");
+    if !same(&Value::Object(found), &Value::Object(defaults)) {
+        return State::Theirs;
+    }
+    State::Defaults(
+        version
+            .as_ref()
+            .and_then(read_version)
+            .unwrap_or(WRITTEN_VERSION),
+    )
+}
+
+fn read_version(v: &Value) -> Option<Version> {
+    Some(Version {
+        major: v.get("Major")?.as_u64()?,
+        minor: v.get("Minor")?.as_u64()?,
+        patch: v.get("Patch")?.as_u64()?,
+    })
+}
+
+/// JSON equality with numbers compared as numbers: the plugin writes its floats through
+/// Newtonsoft, and a value written `1.0` by one framework and `1` by another is the same setting.
+fn same(a: &Value, b: &Value) -> bool {
+    match (a, b) {
+        (Value::Number(x), Value::Number(y)) => match (x.as_f64(), y.as_f64()) {
+            (Some(x), Some(y)) => (x - y).abs() < 1e-6,
+            _ => false,
+        },
+        (Value::Object(x), Value::Object(y)) => {
+            x.len() == y.len() && x.iter().all(|(k, v)| y.get(k).is_some_and(|w| same(v, w)))
+        }
+        (Value::Array(x), Value::Array(y)) => {
+            x.len() == y.len() && x.iter().zip(y).all(|(v, w)| same(v, w))
+        }
+        _ => a == b,
+    }
+}
+
+/// The banner, as the file to write for `state`. `None` for a config that is kept.
+pub fn banner_for(state: State) -> Option<String> {
+    match state {
+        State::Missing => Some(render(BANNER, Some(WRITTEN_VERSION))),
+        State::Defaults(version) => Some(render(BANNER, Some(version))),
+        State::Theirs => None,
+    }
+}
+
+/// One look: the eleven settings PopupNotifications has.
+struct Look {
+    left: &'static str,
+    bottom: &'static str,
+    width: &'static str,
+    height: &'static str,
+    spacing: &'static str,
+    close: bool,
+    alpha: &'static str,
+    font: &'static str,
+    font_size: u32,
+}
+
+/// PopupNotifications 0.2.1's `GetBaseConfig()`: a small grey box at the right of the screen.
+const DEFAULTS: Look = Look {
+    left: "0.8",
+    bottom: "0.78",
+    width: "0.19",
+    height: "0.1",
+    spacing: "0.01",
+    close: true,
+    alpha: "0.5",
+    font: "droidsansmono.ttf",
+    font_size: 12,
+};
+
+/// The recommended look (9d player session, 2026-10-09): a banner across the top of the screen.
+const BANNER: Look = Look {
+    left: "0.15",
+    bottom: "0.87",
+    width: "0.7",
+    height: "0.07",
+    spacing: "0.005",
+    close: false,
+    alpha: "0.8",
+    font: "robotocondensed-bold.ttf",
+    font_size: 18,
+};
+
+/// The config file, laid out as the plugin writes it. Duration, the most shown, both colours and
+/// the close button's transparency are the plugin's own in both looks.
+fn render(look: Look, version: Option<Version>) -> String {
+    let version = version.unwrap_or(WRITTEN_VERSION);
+    format!(
+        r##"{{
+  "Notification duration (in seconds)": 8,
+  "Maximum notifications shown at any time": 6,
+  "UI Positioning": {{
+    "Position of the left side of notification (0.0 - 1.0)": {left},
+    "Position of the bottom of noticiation (0.0 - 1.0)": {bottom},
+    "Width (0.0 - 1.0)": {width},
+    "Height (0.0 - 1.0)": {height},
+    "Space between notification (0.0 - 1.0)": {spacing}
+  }},
+  "UI Options": {{
+    "Show close button": {close},
+    "Panel color (hex)": "#2b2b2b",
+    "Panel transparency (0.0 - 1.0)": {alpha},
+    "Close button color (hex)": "#d85540",
+    "Close button transparency (0.0 - 1.0)": 0.5,
+    "Font": "{font}",
+    "Font size": {font_size}
+  }},
+  "Version": {{
+    "Major": {major},
+    "Minor": {minor},
+    "Patch": {patch}
+  }}
+}}"##,
+        left = look.left,
+        bottom = look.bottom,
+        width = look.width,
+        height = look.height,
+        spacing = look.spacing,
+        close = look.close,
+        alpha = look.alpha,
+        font = look.font,
+        font_size = look.font_size,
+        major = version.major,
+        minor = version.minor,
+        patch = version.patch,
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::util::TempDir;
+
+    /// The file PopupNotifications 0.2.1 wrote on both rigs at its first load (2026-10-09).
+    const RIG_DEFAULTS: &str = r##"{
+  "Notification duration (in seconds)": 8,
+  "Maximum notifications shown at any time": 6,
+  "UI Positioning": {
+    "Position of the left side of notification (0.0 - 1.0)": 0.8,
+    "Position of the bottom of noticiation (0.0 - 1.0)": 0.78,
+    "Width (0.0 - 1.0)": 0.19,
+    "Height (0.0 - 1.0)": 0.1,
+    "Space between notification (0.0 - 1.0)": 0.01
+  },
+  "UI Options": {
+    "Show close button": true,
+    "Panel color (hex)": "#2b2b2b",
+    "Panel transparency (0.0 - 1.0)": 0.5,
+    "Close button color (hex)": "#d85540",
+    "Close button transparency (0.0 - 1.0)": 0.5,
+    "Font": "droidsansmono.ttf",
+    "Font size": 12
+  },
+  "Version": {
+    "Major": 0,
+    "Minor": 2,
+    "Patch": 1
+  }
+}"##;
+
+    #[test]
+    fn a_missing_config_gets_the_banner_with_a_version() {
+        let dir = TempDir::new("rg-popup-missing").unwrap();
+        let state = inspect(&dir.path().join(FILE));
+        assert_eq!(state, State::Missing);
+        let written: Value = serde_json::from_str(&banner_for(state).unwrap()).unwrap();
+        assert_eq!(written["UI Positioning"]["Width (0.0 - 1.0)"], 0.7);
+        assert_eq!(written["UI Options"]["Show close button"], false);
+        assert_eq!(written["UI Options"]["Font"], "robotocondensed-bold.ttf");
+        assert_eq!(written["UI Options"]["Font size"], 18);
+        // Without a version the plugin resets the file to its defaults at load.
+        assert_eq!(written["Version"]["Minor"], 2);
+    }
+
+    #[test]
+    fn the_plugins_own_defaults_are_replaced_and_their_version_kept() {
+        assert_eq!(
+            classify(RIG_DEFAULTS.as_bytes()),
+            State::Defaults(WRITTEN_VERSION)
+        );
+        let later = RIG_DEFAULTS.replace("\"Patch\": 1", "\"Patch\": 4");
+        let state = classify(later.as_bytes());
+        assert_eq!(
+            state,
+            State::Defaults(Version {
+                major: 0,
+                minor: 2,
+                patch: 4
+            })
+        );
+        assert!(banner_for(state).unwrap().contains("\"Patch\": 4"));
+        // A whole number written as a float is still the default.
+        let floats = RIG_DEFAULTS.replace("\"Font size\": 12", "\"Font size\": 12.0");
+        assert!(matches!(classify(floats.as_bytes()), State::Defaults(_)));
+    }
+
+    #[test]
+    fn the_rendered_defaults_are_the_file_the_plugin_writes() {
+        let ours: Value = serde_json::from_str(&render(DEFAULTS, None)).unwrap();
+        let rig: Value = serde_json::from_str(RIG_DEFAULTS).unwrap();
+        assert_eq!(ours, rig);
+    }
+
+    #[test]
+    fn any_change_keeps_the_whole_config() {
+        for changed in [
+            RIG_DEFAULTS.replace("\"Font size\": 12", "\"Font size\": 14"),
+            RIG_DEFAULTS.replace(
+                "\"Notification duration (in seconds)\": 8",
+                "\"Notification duration (in seconds)\": 9",
+            ),
+            RIG_DEFAULTS.replace("#2b2b2b", "#000000"),
+            render(BANNER, None),
+            "{ not json".to_string(),
+            "[]".to_string(),
+        ] {
+            let state = classify(changed.as_bytes());
+            assert_eq!(state, State::Theirs, "{changed}");
+            assert_eq!(banner_for(state), None);
+        }
+    }
+
+    #[test]
+    fn a_config_with_a_setting_added_or_missing_is_theirs() {
+        let mut v: Value = serde_json::from_str(RIG_DEFAULTS).unwrap();
+        v["Extra"] = Value::Bool(true);
+        assert_eq!(classify(v.to_string().as_bytes()), State::Theirs);
+        let mut v: Value = serde_json::from_str(RIG_DEFAULTS).unwrap();
+        v.as_object_mut().unwrap().remove("UI Options");
+        assert_eq!(classify(v.to_string().as_bytes()), State::Theirs);
+    }
+}