Expose credits_remaining (purchased minus cycle overspend) in broker usage + admin overview

app/main.py

@@ -589,11 +589,15 @@ def compute_max_budget(allowance: float, credit_balance: float, team_spend: floa
     allowance. The total spendable cap is simply `allowance + credit_balance`
     — credits never shrink the allowance; they extend it.
 
+    `credit_balance` is the TOTAL purchased (the ledger's lifetime sum); the
+    amount still available this cycle is `credit_balance - credits_used`.
+
     `team_spend` is the member's spend so far this cycle (from LiteLLM). It is
     used only to split the spend between allowance vs credits for display, NOT
     to reduce the cap.
 
-    Returns {"max_budget", "allowance_used", "credits_used"} for dashboards.
+    Returns {"max_budget", "allowance_used", "credits_used", "credits_remaining"}
+    for dashboards.
     """
     max_budget = allowance + credit_balance
     if team_spend is None:
@@ -601,6 +605,7 @@ def compute_max_budget(allowance: float, credit_balance: float, team_spend: floa
             "max_budget": max_budget,
             "allowance_used": 0.0,
             "credits_used": 0.0,
+            "credits_remaining": credit_balance,
         }
     allowance_used = min(max(team_spend, 0.0), allowance)
     credits_used = max(0.0, team_spend - allowance)
@@ -608,6 +613,7 @@ def compute_max_budget(allowance: float, credit_balance: float, team_spend: floa
         "max_budget": max_budget,
         "allowance_used": allowance_used,
         "credits_used": credits_used,
+        "credits_remaining": max(0.0, credit_balance - credits_used),
     }
 
 
@@ -2170,6 +2176,7 @@ async def admin_overview(request: Request):
                 "manual": email.lower() in MANUAL_MEMBERS,
                 "balance": float(balance) if balance is not None else MEMBER_BUDGET,
                 "credit_balance": credits,
+                "credits_remaining": max(0.0, credits - eff["credits_used"]),
                 "allowance_used": eff["allowance_used"],
                 "credits_used": eff["credits_used"],
                 "spend": spend,
@@ -2469,6 +2476,7 @@ async def broker_get_usage(email: str, days: int = 0) -> dict:
                 "balance": balance,
                 "allowance": allowance,
                 "credits": credits,
+                "credits_remaining": max(0.0, credits - max(0.0, spend - allowance)),
                 "spend": spend,
                 "all_time_spend": round(all_time_spend, 2),
                 "remaining": max(balance - spend, 0.0),
@@ -2541,6 +2549,7 @@ async def broker_get_usage(email: str, days: int = 0) -> dict:
         "balance": balance,
         "allowance": allowance,
         "credits": credits,
+        "credits_remaining": max(0.0, credits - max(0.0, spend - allowance)),
         "spend": spend,
         "all_time_spend": all_time_spend,
         "remaining": max(balance - spend, 0.0),