portal: budget notice -> generic low-balance wording, $2 floor, username, once per crossing

Wording no longer names an allowance or a credit pack: it says balance, so it is true whether the member is short on allowance, on purchased credit, or both. Trigger is an absolute $2 floor on remaining budget rather than a percentage, so it means the same at any budget size. Recipient greeting uses members.slug (the username) instead of the email local part, which produced 'Hi n,'. The once-only latch now clears when the balance rises back above the floor, so it fires once per crossing rather than once per budget cycle. BUDGET_NOTICES stays off.

app/main.py

@@ -3971,7 +3971,11 @@ async def index():
 # link today; the Open Collective contribution page is what actually credits a
 # member (the webhook settles contributions into credits).
 
-BUDGET_WARN_AT = 0.80          # fraction of the cap that triggers the warning
+# Generic on purpose: the balance can be short because the monthly allowance is spent,
+# because purchased credit is spent, or a mix — the letter says "balance" so it is true
+# either way. The trigger is an absolute floor, not a percentage, so it means the same
+# thing to a member on a $15 allowance and a member on $35.
+BUDGET_LOW_WATER = float(os.environ.get("BUDGET_LOW_WATER", "2.00"))
 
 PINE_LOGO_SVG = """<svg width="56" height="56" viewBox="0 0 130 130" fill="none" xmlns="http://www.w3.org/2000/svg" aria-hidden="true">
                 <circle cx="65" cy="14" r="5" fill="#5b8c5a"/>
@@ -4021,38 +4025,34 @@ def _ensure_budget_notices_table(conn) -> None:
 
 
 def budget_notice_email(
-    name: str, level: str, spend: float, budget: float, pack_url: str
+    name: str, spend: float, budget: float, remaining: float, pack_url: str
 ) -> tuple[str, str, str]:
-    """Build a budget notice (subject, text, html).
+    """Build the low-balance notice (subject, text, html).
 
-    Deliberately the same shell as welcome_email(): cream background, white card,
-    forest-green button, inline pine-tree mark, table-based layout, no external
-    assets. Only the words and the call to action differ, so a member sees one
-    consistent co-op identity rather than a system notice bolted on beside it.
+    Deliberately generic about where the balance came from: a member may be short
+    because the monthly allowance is spent, because credit they bought is spent, or
+    a mix of both. The wording says "balance" so it is true either way, and it names
+    no mechanism a member would have to reconcile against their own dashboard.
+
+    Same shell as welcome_email(): cream background, white card, forest-green
+    button, inline pine-tree mark, table-based layout, no external assets.
     """
-    pct = (spend / budget * 100.0) if budget else 0.0
-    if level == "exhausted":
-        subject = "Your monthly Inference Cooperative credit is used up"
-        heading = "You've used your monthly credit"
-        lede = ("Your full monthly credit is used, so chat and API requests will stop "
-                "until your credit resets or you add more.")
-    else:
-        subject = f"You've used {pct:.0f}% of your monthly Inference Cooperative credit"
-        heading = f"You're at {pct:.0f}% of your monthly credit"
-        lede = ("You're getting close to the end of your monthly credit. When it runs "
-                "out, chat and API requests stop until it resets.")
+    subject = "Your Inference Cooperative balance is running low"
+    heading = "Your balance is running low"
+    lede = (f"You have ${remaining:.2f} of your ${budget:.2f} balance left. When it "
+            "runs out, chat and API requests stop until you add more. Nothing else "
+            "about your account changes.")
 
-    money = f"${spend:.2f} of ${budget:.2f} used"
+    money = f"${remaining:.2f} remaining"
     text = (
         f"Hi {name},\n\n"
         f"{lede}\n\n"
         f"{money}\n\n"
-        "If you'd like more, credit packs add to your account on top of the monthly "
-        "credit. They never expire, carry over month to month, and are only drawn on "
-        "once your monthly credit is used:\n\n"
+        "If you'd like to keep going, you can add to your balance here:\n\n"
         f"{pack_url}\n\n"
-        "Nothing else changes — your membership, your data and your account stay as "
-        "they are. Questions? Reply to this email or write to info@inference.coop.\n\n"
+        "This is the only notice of its kind you'll get until your balance goes back "
+        "above the line and runs low again. Questions? Reply to this email or write to "
+        "info@inference.coop.\n\n"
         "— The Inference Cooperative\n"
     )
     html = f"""<!DOCTYPE html>
@@ -4073,13 +4073,13 @@ def budget_notice_email(
               <h1 style="margin:0 0 12px;font-size:24px;font-weight:700;color:#2d3327;">{heading}</h1>
               <p style="margin:0 0 8px;font-size:16px;color:#6b7a62;line-height:1.5;">{lede}</p>
               <p style="margin:0 0 24px;font-size:15px;color:#2d3327;line-height:1.5;"><strong>{money}</strong></p>
-              <a href="{pack_url}" style="display:inline-block;background:#5b8c5a;color:#ffffff;text-decoration:none;padding:14px 36px;border-radius:999px;font-size:16px;font-weight:600;">Add credits</a>
-              <p style="margin:28px 0 0;font-size:13px;color:#94a08c;line-height:1.5;">Credit packs never expire, carry over month to month, and are drawn on only after your monthly credit is used.</p>
+              <a href="{pack_url}" style="display:inline-block;background:#5b8c5a;color:#ffffff;text-decoration:none;padding:14px 36px;border-radius:999px;font-size:16px;font-weight:600;">Add to your balance</a>
+              <p style="margin:28px 0 0;font-size:13px;color:#94a08c;line-height:1.5;">This is the only notice of its kind you'll get until your balance goes back above the line and runs low again.</p>
             </td>
           </tr>
           <tr>
             <td align="center" style="padding-top:24px;font-size:13px;color:#94a08c;line-height:1.6;">
-              Nothing else changes — your membership, your data and your account stay as they are.<br>
+              Nothing else about your account changes.<br>
               Questions? Reply to this email or write to <a href="mailto:info@inference.coop" style="color:#6b7a62;">info@inference.coop</a>.<br>
               <span style="color:#2d3327;">The Inference Cooperative</span> &middot; inference.coop
             </td>
@@ -4094,11 +4094,11 @@ def budget_notice_email(
 
 
 async def budget_notice_sweep(send: bool = False) -> dict:
-    """Find members near or over their monthly cap, and optionally email them.
+    """Find members whose balance has fallen below the low-water mark, and optionally email.
 
-    `send=False` is a preview: it computes exactly who would be written to, with
-    the numbers, and sends nothing. `send=True` emails and records the send — the
-    caller is responsible for requiring BUDGET_NOTICES=on first.
+    `send=False` is a preview: it computes exactly who would be written to, with the
+    numbers, and sends nothing. `send=True` emails and records the send — the caller
+    is responsible for requiring BUDGET_NOTICES=on first.
     """
     mode = budget_notices_enabled()
     if send and mode != "on":
@@ -4107,15 +4107,18 @@ async def budget_notice_sweep(send: bool = False) -> dict:
     conn = get_db()
     _ensure_budget_notices_table(conn)
     cols = {r[1] for r in conn.execute("PRAGMA table_info(members)")}
-    name_col = "name" if "name" in cols else ("display_name" if "display_name" in cols else None)
-    sel = "SELECT email" + (f", {name_col}" if name_col else "") + " FROM members WHERE active = 1"
+    # There is no name column in `members` — `slug` is the username (e.g. ntnsndr). Falling
+    # back to the email local part produced "Hi n," for the operator, which is how this was
+    # caught. Prefer the username; say "there" rather than inventing a name.
+    ident = "slug" if "slug" in cols else None
+    sel = "SELECT email" + (f", {ident}" if ident else "") + " FROM members WHERE active = 1"
     rows = conn.execute(sel).fetchall()
 
     pack = credit_pack_url()
     preview, sent, skipped = [], 0, 0
     for row in rows:
         email = row[0]
-        name = (row[1] if len(row) > 1 and row[1] else str(email).split("@")[0])
+        name = ((row[1] or "").strip() if len(row) > 1 else "") or "there"
         team_id = await litellm_team_id_for_email(email)
         if not team_id:
             skipped += 1
@@ -4124,27 +4127,26 @@ async def budget_notice_sweep(send: bool = False) -> dict:
         budget = stats.get("max_budget")
         spend = float(stats.get("spend") or 0.0)
         if not budget or budget <= 0:
-            skipped += 1                                    # unlimited: nothing to warn about
+            skipped += 1                                    # no cap configured: nothing to warn about
             continue
-        cycle = str(stats.get("budget_reset_at") or stats.get("reset_at") or "cycle")[:19]
-        if spend >= budget:
-            level = "exhausted"
-        elif spend >= BUDGET_WARN_AT * budget:
-            level = "warning"
-        else:
+
+        remaining = float(budget) - spend
+        if remaining >= BUDGET_LOW_WATER:
+            # Back above the line — they added funds, or the allowance reset. Clear the latch so
+            # the NEXT crossing sends a fresh notice. That is what makes it once each time, and
+            # it is why this is a latch rather than a key on the budget cycle.
+            conn.execute("DELETE FROM budget_notices WHERE email = ?", (email,))
+            conn.commit()
             continue
-        already = conn.execute(
-            "SELECT 1 FROM budget_notices WHERE email = ? AND level = ? AND cycle = ?",
-            (email, level, cycle),
-        ).fetchone()
-        if already:
-            skipped += 1
+        if conn.execute("SELECT 1 FROM budget_notices WHERE email = ?", (email,)).fetchone():
+            skipped += 1                                    # already told them for this crossing
             continue
-        subject, text_body, html_body = budget_notice_email(name, level, spend, budget, pack)
+
+        subject, text_body, html_body = budget_notice_email(name, spend, budget, remaining, pack)
         entry = {
-            "email": email, "level": level,
+            "email": email, "remaining": round(remaining, 2),
             "spend": round(spend, 2), "budget": round(budget, 2),
-            "pct": round(spend / budget * 100, 1), "cycle": cycle,
+            "resets": str(stats.get("budget_reset_at") or stats.get("reset_at") or "")[:19],
         }
         if send:
             ok = send_email(email, subject, text_body, html_body)
@@ -4152,15 +4154,13 @@ async def budget_notice_sweep(send: bool = False) -> dict:
             if ok:
                 conn.execute(
                     "INSERT OR REPLACE INTO budget_notices"
-                    " (email, level, cycle, sent_at, detail) VALUES (?, ?, ?, datetime('now'), ?)",
-                    (email, level, cycle, f"spend={spend:.4f} budget={budget:.4f}"),
+                    " (email, level, cycle, sent_at, detail) VALUES (?, 'low', ?, datetime('now'), ?)",
+                    (email, entry["resets"] or "crossing", f"remaining={remaining:.4f}"),
                 )
                 conn.commit()
                 sent += 1
         else:
             entry["subject"] = subject
-            preview.append(entry)
-            continue
         preview.append(entry)
     conn.close()
     if send: