test(rustd): five assertions that had never been run, and were wrong

The integration lane had never executed on this branch. Running it turned up
five red tests, none of them a production defect — every one an assertion or a
fixture that encoded something the daemon does not do.

  - `test_renew_coverage_refuses_an_empty_wallet` asserted the CREDITS refusal
    and got the BUDGET one. `claude-fixture` is in no catalogue, so the estimate
    is `Unpriceable`, its floor is zero, a zero balance covers zero, and the
    credits gate ADMITS — fail-open, and deliberately so: an unpriced model must
    not strand a tenant. A test naming the credits refusal has to seed past that
    rather than assume the default reaches it. The new `seed_model_rate` fixture
    prices the model; its rates are Anthropic-shaped because the issue estimate
    prices a hundred tokens each way and integer division floors anything below
    ten thousand nanos per million to zero.

  - `test_report_dedup_idempotent` asserted the two-rows-per-event invariant
    against a fixture that could only ever produce one. `Leases::record_received`
    opens the narrative log; the receive LEDGER row is `Accounts::debit_receive`,
    reached through `money_gates` on the plane. The fixture drove the store and
    skipped it. Fixed in the fixture — weakening the assertion to one row would
    have deleted the invariant.

  - `test_report_stale_fence_rejected` asserted the lifetime-counter row was
    absent. It is never absent: `INSERT_LEASE_WITH_EVENT` creates it with
    `acquired = 1` at issue. It now pins BOTH `succeeded` and `failed` to zero,
    which is what a wrongly-gated `tally` would actually break.

  - `test_boot_to_ready_on_compose` predated §6 putting four sweepers under the
    supervisor. The four names are now `pub` — as `serve::ACCEPT_LOOP` already
    was — so the test names the same constant the daemon spawns under. A literal
    would survive a rename and leave a sweeper unsupervised, green.

  - `test_only_the_ported_routes_are_mounted` said twelve. §4 mounted the mint.

Also: `docs/architecture/data_flow.md` cited M181, whose spec is in
`docs/v2/pending/`, and the architecture gate resolves pending ids from
`roadmap.md` alone — an architecture page asserts facts about what ships. The
sentence now points at the roadmap instead. Pre-existing, and it is what stood
between this branch and a green `make lint-all`.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>