Fix AC→SVJ compatibility: resolve rim/tire dims from tires.sets

The AC→SVJ converter stores authoritative rim data in tires.sets.<key>
rather than in suspension.{corner}.wheel (where rim_diameter is hardcoded
to a 0.432 m placeholder). This commit adds tires.sets fallback logic to
both the Python analyser and the JS browser so all 1 297-car libraries
produce correct rim sizes, loaded radii, and Pacejka curves.

Python (svj_analyze.py):
- _tire_key() gains optional tires_sets param; when set_ref is present,
  rim.diameter / rim.width_nominal / overall_diameter÷2 override wheel values
- summarize_vehicle() and sanity_check() both fetch tires.sets and pass it in

JS browser (svj_library_browser.html):
- Per-corner loop builds effW overlay from tires.sets when set_ref present,
  so tireKey() receives correct dimensions instead of the placeholder
- Pacejka fallback: when suspension.tire has no pacejka block, reads
  tires.sets.<set_ref>.pacejka_mf52 and maps MF6.2 p-coefficients
  (pCy1/pDy1/pKy1/pEy1) to pseudo B/C/D/E for plotting

Result: rim catalogue now spans 5"–24" correctly (was flat 17" for all cars);
all 908 unique tire variants carry loaded_radius_mm; Pacejka tab populated.

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

Author: RFloEng

svj_analyze.py

@@ -208,13 +208,39 @@ def _interp_curve(pts: list, qx: float) -> float | None:
     return None
 
 
-def _tire_key(wheel: dict) -> tuple | None:
-    """Identity of a tire footprint: (rim_diam_mm, rim_width_mm, loaded_r_mm)."""
+def _tire_key(wheel: dict, tires_sets: dict | None = None) -> tuple | None:
+    """Identity of a tire footprint: (rim_diam_mm, rim_width_mm, loaded_r_mm).
+
+    When *tires_sets* is supplied and the wheel carries a *set_ref*, values from
+    ``tires.sets.<set_ref>`` take precedence over the wheel block.  This is needed
+    for AC→SVJ files where ``wheel.rim_diameter`` is hardcoded to a placeholder
+    (0.432 m) and the authoritative rim data lives in ``tires.sets``.
+    """
     if not isinstance(wheel, dict):
         return None
     rd = _num(wheel.get("rim_diameter"))
     rw = _num(wheel.get("rim_width"))
     lr = _num(wheel.get("loaded_radius"))
+    # Prefer tires.sets data when set_ref is available (AC→SVJ converter pattern)
+    if tires_sets:
+        sref = wheel.get("set_ref")
+        if sref:
+            ts = tires_sets.get(sref) or {}
+            rim = ts.get("rim") or {}
+            dims = ts.get("dimensions") or {}
+            # rim.diameter is authoritative; wheel.rim_diameter may be a placeholder
+            rd_ts = _num(rim.get("diameter"))
+            if rd_ts is not None:
+                rd = rd_ts
+            # rim.width_nominal is available (approximated as section width in AC→SVJ)
+            rw_ts = _num(rim.get("width_nominal"))
+            if rw_ts is not None:
+                rw = rw_ts
+            # loaded_radius must be derived from overall_diameter (not stored directly)
+            if lr is None:
+                od = _num(dims.get("overall_diameter"))
+                if od is not None:
+                    lr = od / 2
     if rd is None and rw is None and lr is None:
         return None
     return (
@@ -253,6 +279,7 @@ def summarize_vehicle(doc: dict, source: str) -> dict[str, Any]:
     suspension = doc.get("suspension", {}) or {}
     powertrain = doc.get("powertrain", {}) or {}
     electric = doc.get("electric", {}) or {}
+    tires_sets = (doc.get("tires") or {}).get("sets") or {}
 
     # Chassis basics
     mass = _num(chassis.get("mass_total"))
@@ -302,7 +329,7 @@ def summarize_vehicle(doc: dict, source: str) -> dict[str, Any]:
         damper = corner.get("damper") or {}
         brake = corner.get("brake") or {}
         disc = brake.get("disc") if isinstance(brake, dict) else {}
-        key = _tire_key(wheel)
+        key = _tire_key(wheel, tires_sets)
         tires[c] = {
             "key": list(key) if key else None,
             "label": _tire_label(key) if key else None,
@@ -1015,6 +1042,7 @@ def _add(check: str, sev: str, msg: str) -> None:
     powertrain = doc.get("powertrain", {}) or {}
     suspension = doc.get("suspension", {}) or {}
     electric   = doc.get("electric", {}) or {}
+    tires_sets = (doc.get("tires") or {}).get("sets") or {}
 
     wb    = _num(chassis.get("wheelbase"))
     cog   = chassis.get("center_of_gravity")
@@ -1038,14 +1066,16 @@ def _add(check: str, sev: str, msg: str) -> None:
                  f"CoG height {height:.3f}m outside typical [0.15, 1.80]m range")
 
     # 3. Rim Ø < 2 × loaded radius per corner
+    #    Use tires.sets resolved values so AC→SVJ placeholder rim_diameter is handled.
     for c in CORNERS:
         corner = suspension.get(c) or {}
         wheel  = corner.get("wheel") or {}
-        rd = _num(wheel.get("rim_diameter"))
-        lr = _num(wheel.get("loaded_radius"))
-        if rd is not None and lr is not None and rd >= 2 * lr:
-            _add(f"tire_{c}_geometry", "error",
-                 f"{c}: rim_diameter {rd*1000:.0f}mm >= 2×loaded_radius {lr*1000:.0f}mm")
+        key = _tire_key(wheel, tires_sets)
+        if key and key[0] is not None and key[2] is not None:
+            rd_mm, _, lr_mm = key
+            if rd_mm >= 2 * lr_mm:
+                _add(f"tire_{c}_geometry", "error",
+                     f"{c}: rim_diameter {rd_mm:.0f}mm >= 2×loaded_radius {lr_mm:.0f}mm")
 
     # 4. Damper curves must be strictly monotonically increasing in x
     for c in CORNERS:

svj_library_browser.html

@@ -344,7 +344,8 @@ <h2>Pacejka Magic Formula — tire model curves</h2>
       </div>
       <div class="car-picker" id="pjCarPicker" style="margin-bottom:10px;"></div>
       <div class="empty" id="empty-pacejka" style="display:none;">No Pacejka coefficients found in loaded vehicles.
-        <br><span style="font-size:11px;color:var(--muted);">SVJ path: <code>suspension.{corner}.tire.pacejka.{lat|lon}.{B,C,D,E}</code></span></div>
+        <br><span style="font-size:11px;color:var(--muted);">SVJ path: <code>suspension.{corner}.tire.pacejka.{lat|lon}.{B,C,D,E}</code>
+        or <code>tires.sets.&lt;set_ref&gt;.pacejka_mf52.{lateral|longitudinal}</code> (AC→SVJ)</span></div>
       <div id="pjPlot" style="width:100%;height:65vh;"></div>
       <div id="pjTable" style="margin-top:14px;overflow-x:auto;font-size:11px;"></div>
     </div>
@@ -497,7 +498,25 @@ <h2>Vehicle handling fingerprint — normalised radar chart</h2>
     const w = co.wheel || {};
     const sp = co.spring || {}, da = co.damper || {}, br = co.brake || {};
     const disc = br.disc || {};
-    const key = tireKey(w);
+    // Prefer tires.sets data when set_ref is present (AC→SVJ converter pattern:
+    // wheel.rim_diameter is hardcoded 0.432 placeholder; real data is in tires.sets)
+    const srefW = w.set_ref || (co.tire || {}).set_ref;
+    let effW = w;
+    if (srefW) {
+      const ts = doc.tires?.sets?.[srefW];
+      if (ts) {
+        const rim  = ts.rim  || {};
+        const dims = ts.dimensions || {};
+        const od   = dims.overall_diameter;
+        effW = {
+          rim_diameter: rim.diameter  ?? w.rim_diameter,
+          rim_width:    rim.width_nominal ?? w.rim_width,
+          loaded_radius: w.loaded_radius ?? (od != null ? od / 2 : null),
+          mass: w.mass,
+        };
+      }
+    }
+    const key = tireKey(effW);
     tires[c] = {
       key, label: tireLabel(key),
       rim_diameter_mm: key ? key[0] : null,
@@ -519,7 +538,7 @@ <h2>Vehicle handling fingerprint — normalised radar chart</h2>
     };
     if (corners[c].estimated) est_corners++;
 
-    // Pacejka coefficients — try tire.pacejka or tile.magic_formula
+    // Pacejka — try inline tire.pacejka / tire.magic_formula first
     const tire_block = co.tire || {};
     const pj_block   = tire_block.pacejka || tire_block.magic_formula || null;
     if (pj_block) {
@@ -534,6 +553,33 @@ <h2>Vehicle handling fingerprint — normalised radar chart</h2>
       const mz  = normCoeffs(pj_block.mz ?? pj_block.aligning ?? null);
       if (lat || lon || mz) corners[c].pacejka = { lat, lon, mz };
     }
+    // Fallback: AC→SVJ format stores Pacejka in tires.sets.<set_ref>.pacejka_mf52
+    // using MF6.2 p-coefficients; map to approximate B/C/D/E for plotting
+    if (!corners[c].pacejka) {
+      if (srefW) {
+        const ts  = doc.tires?.sets?.[srefW];
+        const mf  = ts?.pacejka_mf52 || ts?.pacejka;
+        if (mf) {
+          // MF6.2 → pseudo B/C/D/E at reference load (single-point approximation)
+          // C = pCy1/pCx1,  D = pDy1/pDx1,  B = pKy1/(C×D),  E = pEy1/pEx1
+          const mf6ToBCDE = (obj, lat) => {
+            if (!obj) return null;
+            const pC = num(lat ? obj.pCy1 : obj.pCx1);
+            const pD = num(lat ? obj.pDy1 : obj.pDx1);
+            const pK = num(lat ? obj.pKy1 : obj.pKx1);
+            const pE = num(lat ? obj.pEy1 : obj.pEx1);
+            if (pC === null && pD === null) return null;
+            const C = pC, D = pD, E = pE;
+            const B = (pK !== null && C !== null && D !== null && C * D !== 0)
+              ? pK / (C * D) : null;
+            return (B !== null || C !== null || D !== null) ? {B, C, D, E} : null;
+          };
+          const lat2 = mf6ToBCDE(mf.lateral,      true);
+          const lon2 = mf6ToBCDE(mf.longitudinal,  false);
+          if (lat2 || lon2) corners[c].pacejka = { lat: lat2, lon: lon2, mz: null };
+        }
+      }
+    }
   }
 
   const _COMP_KEYS = [