fix(simulation): address PR #108 review — LEFT JOIN, JSON output, atmosphere default

Review fixes:
- corridor-status: INNER JOIN → LEFT JOIN so systems without gate
  records are included in counts instead of silently excluded
- corridor-status: output as JSON (serde_json) matching all other
  atlas commands, instead of plain-text ASCII table
- generate_body_matrix: emit atmosphere "standard" instead of
  "breathable" to match committed-system conventions
- Doc header: add corridor-status usage example
- CHANGELOG: note stale habitable_planet_count in pre-fix systems

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -10,7 +10,9 @@ Format based on [Keep a Changelog](https://keepachangelog.com/).
 - `corridor-status` subcommand for atlas CLI — shows remaining unfinished systems grouped by geographic sector and hop distance (#744)
 
 ### Fixed
-- `habitable_planet_count` filter now accepts both "breathable" and "standard" atmosphere values — previously all committed systems reported 0 habitable planets (#762)
+- `habitable_planet_count` filter now accepts both "breathable" and "standard" atmosphere values — previously all committed systems reported 0 habitable planets (#762). Systems committed before this fix may have stale `habitable_planet_count = 0`; re-commit to update.
+- `corridor-status` uses LEFT JOIN so systems without gate records are included in counts
+- `generate_body_matrix` now emits `atmosphere: "standard"` (was "breathable") to match committed-system conventions
 
 ## [v0.1.29] — 2026-04-03
 

server/src/bin/atlas.rs

@@ -10,6 +10,7 @@
 //! tooling/atlas show-body "GJ 15Ab"
 //! tooling/atlas add-body --system "GJ 15A" --type planet --orbit 1 --id "GJ 15Ab"
 //! tooling/atlas stats
+//! tooling/atlas corridor-status  # remaining systems by corridor/hop
 //! tooling/atlas populate  # bulk classifier pass
 //!
 //! # Direct:
@@ -911,7 +912,7 @@ fn generate_body_matrix(
             surface_gravity: Some(0.9),
             orbital_period_days: Some(365.0),
             rotation_period_hours: Some(24.0),
-            atmosphere: Some("breathable".into()),
+            atmosphere: Some("standard".into()),
             biome_summary: Some("temperate".into()),
             hydrosphere: None,
             economic_role: None,
@@ -943,7 +944,7 @@ fn generate_body_matrix(
             surface_gravity: Some(0.85),
             orbital_period_days: Some(400.0),
             rotation_period_hours: Some(26.0),
-            atmosphere: Some("breathable".into()),
+            atmosphere: Some("standard".into()),
             biome_summary: Some("temperate".into()),
             hydrosphere: None,
             economic_role: None,
@@ -1999,26 +2000,28 @@ fn format_population(pop: i64) -> String {
 fn cmd_corridor_status(conn: &Connection) {
     // Query unfinished systems grouped by geographic_sector and hop_distance_from_gateway.
     // "Unfinished" = no rows in bodies for this system_id.
+    // LEFT JOIN so systems with no gate record are still counted (hop = NULL → "?").
     let mut stmt = conn
         .prepare(
             "SELECT s.geographic_sector, g.hop_distance_from_gateway, COUNT(*) AS remaining
              FROM star_systems s
-             JOIN system_gates g ON s.system_id = g.system_id
+             LEFT JOIN system_gates g ON s.system_id = g.system_id
              WHERE s.system_id NOT IN (SELECT DISTINCT system_id FROM bodies)
              GROUP BY s.geographic_sector, g.hop_distance_from_gateway
              ORDER BY s.geographic_sector, g.hop_distance_from_gateway",
         )
         .unwrap();
 
-    struct Row {
+    #[derive(Serialize)]
+    struct CorridorRow {
         sector: Option<String>,
         hop: Option<i32>,
         remaining: i64,
     }
 
-    let rows: Vec<Row> = stmt
+    let rows: Vec<CorridorRow> = stmt
         .query_map([], |row| {
-            Ok(Row {
+            Ok(CorridorRow {
                 sector: row.get(0)?,
                 hop: row.get(1)?,
                 remaining: row.get(2)?,
@@ -2029,31 +2032,39 @@ fn cmd_corridor_status(conn: &Connection) {
         .collect();
 
     if rows.is_empty() {
-        println!("All systems have bodies authored.");
+        #[derive(Serialize)]
+        struct EmptyResult {
+            total: i64,
+            message: &'static str,
+            corridors: Vec<()>,
+        }
+        println!(
+            "{}",
+            serde_json::to_string_pretty(&EmptyResult {
+                total: 0,
+                message: "All systems have bodies authored.",
+                corridors: vec![],
+            })
+            .unwrap()
+        );
         return;
     }
 
-    // Plain text table: corridor | hop | remaining
     let total: i64 = rows.iter().map(|r| r.remaining).sum();
-    println!("{:<30} {:>4}  {:>9}", "Corridor", "Hop", "Remaining");
-    println!("{}", "-".repeat(48));
-    let mut last_sector = String::new();
-    for row in &rows {
-        let sector = row.sector.as_deref().unwrap_or("(unknown)");
-        let hop = row
-            .hop
-            .map(|h| h.to_string())
-            .unwrap_or_else(|| "?".to_string());
-        if sector != last_sector {
-            if !last_sector.is_empty() {
-                println!();
-            }
-            last_sector = sector.to_string();
-        }
-        println!("{:<30} {:>4}  {:>9}", sector, hop, row.remaining);
+
+    #[derive(Serialize)]
+    struct CorridorResult {
+        total: i64,
+        corridors: Vec<CorridorRow>,
     }
-    println!("{}", "-".repeat(48));
-    println!("{:<30} {:>4}  {:>9}", "TOTAL", "", total);
+    println!(
+        "{}",
+        serde_json::to_string_pretty(&CorridorResult {
+            total,
+            corridors: rows,
+        })
+        .unwrap()
+    );
 }
 
 // ---------------------------------------------------------------------------