docs(m164): changelog — metered runs are priced from the catalogue

changelog.mdx

@@ -7,6 +7,24 @@ description: "Stay up to date with the latest agentsfleet product updates, new f
   agentsfleet is in **stealth-mode testing** and pre-production. APIs and agent behavior may change between releases without long deprecation windows. Email [agentsfleet@agentmail.to](mailto:agentsfleet@agentmail.to) if you want a hand calibrating an agent or to join as a design partner.
 </Tip>
 
+<Update label="Aug 13, 2026" tags={["Breaking", "Bug fixes", "API"]}>
+  ## Metered runs are priced from the model catalogue
+
+  A promotional window sat in front of every price. It was a per-tenant timestamp that was nullable with no default, nothing in the product ever wrote it, and an empty value read as "the window is still open" — so every account held it empty and every metered stage priced to zero for the whole life of the account. The window is deleted rather than repaired: pricing resolves from the model catalogue and the execution posture alone, and no rate resolver takes a clock, so a price cannot drift with wall time. Free usage is the starter grant and the balance that drains from it, bounded by `exhausted_at` — the mechanism the product already describes, and now the only one.
+
+  ## Breaking changes
+
+  - **`GET /v1/tenants/me/billing` no longer returns `free_trial`.** The response carries `balance_nanos`, `updated_at`, `is_exhausted`, and `exhausted_at`, which is the whole billing state a client needs. The member is gone from the published schema and from its `required` list, so a client that reads it must stop.
+
+  ## Bug fixes
+
+  - **A metered platform stage is charged the catalogue rate.** Run time and all three token tiers — input, cached, and output — accrue against the credit pool at the rates the catalogue carries, instead of resolving to zero. A `self_managed` stage is unchanged: the run fee only, with token counts recorded and not charged.
+  - **A model the catalogue does not price is refused rather than run for nothing.** The window answered ahead of the catalogue lookup, so a provider-and-model pair with no rate row priced at zero instead of failing. Renewal and settlement now fail closed on an unpriced pair; the lease estimate still admits the run, so an unrated model surfaces as a billing error rather than a silent free run.
+  - **The budget gates can refuse a fleet.** A fleet budget is spent against real rates, so `credit_deducted_nanos` accrues from the first metered slice. While every charge was zero no budget was ever consumed and neither gate could stop anyone.
+  - **The free trial is named early access.** The pricing card reads "Early access", and the answer to "What am I actually paying for?" no longer describes an ending — it used to say metering began "after the trial". Free usage is the starter grant, which ends when the balance does rather than on a date. The rates themselves are unchanged.
+  - **Deleting a fleet erases its memory.** Rows in `memory.memory_entries` are removed with the fleet they belong to. They used to survive it, and because every sweep is scoped by a fleet the caller can enumerate, memory whose fleet was already gone was unreachable by all of them — an erased account kept it indefinitely. The isolation boundary is unchanged: the memory role still holds no grant on `core` and cannot name `core.fleets` at all.
+</Update>
+
 <Update label="Aug 10, 2026" tags={["What's new", "Security", "Integrations"]}>
   ## A fleet with write access always parks for a human