game_data: typed loaders for the combat / character / mission tables

Decode Project Sylpheed's IDXD data model into plain, cloneable structs
(from GP_MAIN_GAME_E.pak; the D/F/I/J/S paks are localized dups):

- Weapon (121), CraftUnit (89, with the AI flight model in .fields),
  Vessel (23, structural component counts), PlayerConfig (24) — the
  full combat balance.
- Character (68 — faction + portrait set), Stage (29 missions:
  location, phases, and the per-stage resource tables it wires up).
- Generic Record / load_records(schema) reads any of the 105 IDXD
  schemas without a bespoke struct.

Each blob = one entity; token[0] names the table, fields are
value-before-key. Named Option<> fields for the common stats + a full
`fields` map; defaulted fields stay None (they're code-resident, not on
disc — honest blanks, never guessed). 8 tests against the real disc.

Examples: iso_map / deep_map census the ISO's formats and IDXD schemas;
dm_extract / dm_rows / dm_roster / mission_map dump the decoded data.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/sylpheed-formats/examples/deep_map.rs

@@ -0,0 +1,59 @@
+use sylpheed_formats::{ratc, idxd::IdxdObject, PakArchive};
+use std::collections::BTreeMap;
+fn main(){
+    let disc=std::env::var("SYLPHEED_DISC").unwrap();
+    // 1. RATC child-type census across the big RATC paks
+    let mut childtypes:BTreeMap<String,u64>=BTreeMap::new();
+    let mut ratc_unparsed=0u64;
+    for pk in ["GP_READY_ROOM","GP_MOVIE_THEATER","GP_DIALOG","GP_DEBRIEFING_PILOTLOG","GP_TITLE","GP_BUNK"]{
+        let Ok(arc)=PakArchive::open(format!("{disc}/dat/{pk}.pak")) else{continue};
+        for e in arc.entries(){
+            let Ok(b)=arc.read(e) else{continue};
+            if !ratc::is_ratc(&b){continue;}
+            match ratc::parse(&b){
+                Some(kids)=> for k in kids{
+                    let ext=k.name.rsplit('.').next().unwrap_or("?").to_lowercase();
+                    *childtypes.entry(ext).or_default()+=1;
+                },
+                None=>ratc_unparsed+=1,
+            }
+        }
+    }
+    println!("=== RATC child-type census (big RATC paks) ===");
+    let mut cv:Vec<_>=childtypes.into_iter().collect(); cv.sort_by_key(|x|std::cmp::Reverse(x.1));
+    for (e,c) in &cv{ println!("  .{e:8} ×{c}"); }
+    println!("  (RATC bundles that failed to parse: {ratc_unparsed})");
+
+    // 2. The 00000002 mystery format (GP_MAIN_GAME_E)
+    let arc=PakArchive::open(format!("{disc}/dat/GP_MAIN_GAME_E.pak")).unwrap();
+    for e in arc.entries(){
+        let Ok(b)=arc.read(e) else{continue};
+        if b.len()>=4 && b[0..4]==[0,0,0,2]{
+            let hx:String=b[..48.min(b.len())].iter().map(|x|format!("{x:02x}")).collect::<Vec<_>>().join(" ");
+            let asc:String=b[..64.min(b.len())].iter().map(|&x|if(0x20..0x7f).contains(&x){x as char}else{'.'}).collect();
+            println!("\n=== 00000002 format sample ({}B) ===\n{hx}\n{asc}",b.len());
+            break;
+        }
+    }
+
+    // 3. Sample the top undecoded IDXD schemas: first tokens (guess semantics)
+    println!("\n=== top undecoded IDXD schemas — sample tokens (semantic hints) ===");
+    let targets:[u32;6]=[0xb412e6d8,0x026379ab,0x43faa517,0x3c5b0549,0x6ab4825a,0x0426e81d];
+    for want in targets{
+        let mut shown=false;
+        for e in arc.entries(){
+            if shown{break;}
+            let Ok(b)=arc.read(e) else{continue};
+            if b.len()<12 || &b[0..4]!=b"IDXD"{continue;}
+            let s=u32::from_be_bytes([b[8],b[9],b[10],b[11]]);
+            if s!=want{continue;}
+            if let Ok(o)=IdxdObject::parse(&b){
+                let t=o.tokens();
+                let sample:Vec<String>=t.iter().take(14).map(|s|{let s=s.chars().take(18).collect::<String>();s}).collect();
+                println!("  {want:08x}: {sample:?}");
+                shown=true;
+            }
+        }
+        if !shown{ println!("  {want:08x}: (parse failed / not found)"); }
+    }
+}