feat(store): add fsn store i18n subcommand (status/set/check)

- I18nCommand enum: Status, Set { lang }, Check
- status: fetch Node/catalog/i18n.toml, show completeness + schema_version
- set/check: stubs, TODO implement download + activation
- BUNDLED_SCHEMA_VERSION const for schema mismatch detection

Author: FreeSynergy

cli/crates/fsn-node-cli/src/cli.rs

@@ -219,6 +219,24 @@ pub enum StoreCommand {
     },
     /// Check for available updates
     Update,
+    /// Manage UI language packs
+    I18n {
+        #[command(subcommand)]
+        cmd: I18nCommand,
+    },
+}
+
+#[derive(Subcommand)]
+pub enum I18nCommand {
+    /// Show available languages and their completeness
+    Status,
+    /// Download and activate a language pack
+    Set {
+        /// BCP 47 language code (e.g. "de", "fr", "ja")
+        lang: String,
+    },
+    /// Check if installed language is up to date with the current schema
+    Check,
 }
 
 #[derive(Subcommand)]
@@ -279,6 +297,11 @@ pub async fn run() -> Result<()> {
             StoreCommand::Info { id }       => commands::store::info(&id).await,
             StoreCommand::Install { id }    => commands::store::install(&id).await,
             StoreCommand::Update            => commands::store::update_check().await,
+            StoreCommand::I18n { cmd }      => match cmd {
+                I18nCommand::Status        => commands::store::i18n_status().await,
+                I18nCommand::Set { lang }  => commands::store::i18n_set(&lang).await,
+                I18nCommand::Check         => commands::store::i18n_check().await,
+            },
         },
         Command::Server { cmd }            => match cmd {
             ServerCommand::Setup           => commands::server_setup::run(&root).await,

cli/crates/fsn-node-cli/src/commands/store.rs

@@ -1,4 +1,4 @@
-// `fsn store` — browse and manage the FreeSynergy module store.
+// `fsn store` — browse and manage the FreeSynergy module store and language packs.
 //
 // Uses StoreClient (fsn-store) to fetch the Node.Store catalog and display
 // available modules. Install/update are delegated to `fsn deploy` once
@@ -7,6 +7,10 @@
 use anyhow::{Context, Result};
 use fsn_node_core::store::StoreEntry;
 use fsn_store::StoreClient;
+use toml;
+
+// Schema version bundled with this binary — must match Lib's sync_snippets.py SCHEMA_VERSION.
+const BUNDLED_SCHEMA_VERSION: &str = "1.0.0";
 
 // ── Catalog helper ─────────────────────────────────────────────────────────────
 
@@ -116,3 +120,65 @@ pub async fn update_check() -> Result<()> {
     println!("To update a deployed module, run `fsn update --service <name>`.");
     Ok(())
 }
+
+// ── i18n ───────────────────────────────────────────────────────────────────────
+
+/// One entry from `[[languages]]` in the store's `catalog/i18n.toml`.
+#[derive(serde::Deserialize)]
+struct I18nCatalogEntry {
+    code:           String,
+    name:           String,
+    #[serde(default)]
+    completeness:   u8,
+    #[serde(default)]
+    schema_version: String,
+    // file / sha256 / size are used by the updater, not displayed here
+}
+
+#[derive(serde::Deserialize)]
+struct I18nCatalog {
+    #[serde(default, rename = "languages")]
+    languages: Vec<I18nCatalogEntry>,
+}
+
+/// Show all available language packs from the store catalog with completeness.
+pub async fn i18n_status() -> Result<()> {
+    let client = StoreClient::node_store();
+    let raw = client
+        .fetch_raw("Node/catalog/i18n.toml")
+        .await
+        .context("fetching i18n catalog")?;
+    let catalog: I18nCatalog = toml::from_str(&raw).context("parsing i18n catalog")?;
+
+    if catalog.languages.is_empty() {
+        println!("No language packs available in the store yet.");
+        return Ok(());
+    }
+
+    println!("{:<6} {:<24} {:>5}  {:<8} {}", "CODE", "LANGUAGE", "COMP%", "SCHEMA", "");
+    println!("{}", "─".repeat(58));
+    for e in &catalog.languages {
+        let ok = e.schema_version.is_empty() || e.schema_version == BUNDLED_SCHEMA_VERSION;
+        let marker = if ok { "✓" } else { "⚠ outdated" };
+        let schema = if e.schema_version.is_empty() { BUNDLED_SCHEMA_VERSION } else { &e.schema_version };
+        println!("{:<6} {:<24} {:>4}%  {:<8} {}", e.code, e.name, e.completeness, schema, marker);
+    }
+    println!("\nRequired schema: {BUNDLED_SCHEMA_VERSION}  (⚠ = needs update, run `fsn store i18n set <code>`)");
+    Ok(())
+}
+
+/// Download and activate a language pack.
+pub async fn i18n_set(lang: &str) -> Result<()> {
+    // TODO: fetch merged lang file from store → write to ~/.config/fsn/i18n/{lang}.toml → set active
+    println!("Language pack '{lang}' — download and activation not yet implemented.");
+    println!("Run `fsn store i18n status` to see available packs.");
+    Ok(())
+}
+
+/// Check whether the currently active language pack matches the bundled schema version.
+pub async fn i18n_check() -> Result<()> {
+    // TODO: read active lang from ~/.config/fsn/config.toml, compare schema_version
+    println!("Schema version (bundled): {BUNDLED_SCHEMA_VERSION}");
+    println!("Active language check — not yet implemented.");
+    Ok(())
+}