feat(economic): the 0x0029 issuance producer — token.mint is the one mint channel

[cryptskii]

The producer half of the 0x0029 core/producer split. After this cut the
definition-of-done statement is literally true:

The only way a positive user-token Mint can enter canonical DeviceState is
through an economic admission whose CreditSource is AuthorizedIssuance and
whose immutable 0x0029 evidence independently proves that the committed
token policy authorized that exact asset, amount, recipient lineage/device,
operation digest, and write-once economic position.

One authorization channel

Operation::Mint is now { amount, token_id, policy_commit, message } —
nothing in it asserts issuance authority. The legacy channel is deleted
outright, not disabled: the authorized_by/proof_of_authorization fields
(wire tag 4 layout change, beta wipe), the mint|v2| transition verifier, the
token-state-manager verifier, the TokenAuthority gate on "mint" (burn and
create_token keep it — with a severance pin test), the TokenSDK direct-mint
producer (now a named refusal; its only caller chain was the dBTC deposit
completion, whose success was already structurally impossible against the
builtin accepting arm), and the env-gated dev-seed ERA mint. A second channel
inside the operation is now unrepresentable, which retired the arm's
empty-field guard and its test.

The producer

token.mint follows the frozen acyclic order — resolve → refuse builtins →
load the EXACT committed policy bytes (verified against their own commit) →
run core's parse_issuance_policy + check_issuance_permitted pre-flight →
require this wallet's key among the policy's signers with a locally
satisfiable threshold → freeze the Mint (canonical token id, so a mint by
ticker and one by id commit IDENTICAL bytes) → derive the digest → build the
0x0029 body at the TARGET position → sign → bundle → admission. The evidence
bytes freeze in the same transaction as the advance and the pending admission;
the route reports success only after ECON_ADMITTED.

admitted_self_loop_operation gains a facts_for_position closure (runs
after the target position and operation digest are fixed, before anything
durable) instead of hardcoding CreditSourceFacts::None — one admission
pipeline, no sibling.

The accepting layer's blanket refusal becomes the admission gate: a positive
non-builtin mint requires an attached DsmBacked admission bound to the exact
operation (require_attached_dsm_admission, the faucet/transfer-credit
discipline). Builtin mints stay unconditionally refused. canonical_rebuild
whitelists Mint beside FaucetClaim and credit-Transfers — without that, every
head rebuild would truncate at the first historical mint.

Three core defects this cut's tests caught in #748's verifier

1. The write-set verifier arm did not exist. verify_operation_write_set
   had builder-side facts for issuance but no
   (AuthorizedIssuance, Mint) verification arm — every issuance witness fell
   through to "credit source kind does not match the operation". No mint could
   ever have validated. The arm now pins the shape half (exactly one balance
   credit, no consumed-source leaf, descriptor funds THE credit); the
   semantics stay in the 0x0023 provenance arm. One feat(economic): class 0x0029 AuthorizedIssuanceV1 — the missing source predicate #748 test had pinned the
   defect as the behavior: a defined-but-unsatisfied predicate now correctly
   fails at the PROVENANCE layer (unresolvable evidence) instead of the shape
   wildcard, and the test was re-cut to say so.
2. The evidence address was the wrong form. The evidence DAG addresses
   every object by its INNER content identity (immutable_inner), and the
   resolver's fetch derives the store key from an inner address. The 0x0029
   arm and descriptor committed to the OUTER immutable_addr — so every live
   fetch missed by construction, invisible until the held-mint resume test
   fetched from a real (fake-fleet) quorum. Aligned to inner. Flag: the
   producer-less 0x0026/0x0027 DLV arms carry the identical outer-form
   mismatch; their fix belongs to the PR5/PR6 producer cuts and is recorded
   here so it is not rediscovered the hard way.
3. The committed policy-blob tail could not be parsed (owner-ruled
   conformance repair): the SDK packer always writes the u16 allowlist count —
   an explicit zero under kind NONE — and core read no count for NONE, then
   failed closed on trailing bytes: every allowlist-free token was permanently
   unissuable. Core now parses exactly what the packer commits (NONE ⇒ count
   present and zero; INLINE ⇒ count > 0; flag must agree with payload), pinned
   by SDK→core round-trip controls for both shapes.

Tests

• Honest mint, end to end, foreign-walked: faucet(1) → create(2) →
  mint(3) → unfenced head → a foreign verifier with cleared caches walks
  position 3 through the live 0x0023 arm, fetching the bundle by address from
  the fleet, and yields the Mint.
• Policy shapes refuse by name at the producer: mint/burn disabled;
  allowlist excluding this device; allowlist positive control mints.
• Atomicity: a failed evidence build leaves no advance, no fence, no
  admitted movement, no frozen artifact.
• Held → resume: quorum dies after the staged commit; the mint, its
  pending admission and the exact evidence bytes are all durable; resume
  completes the SAME admission at the signed position with byte-identical
  evidence — nothing re-signed.
• Consume-once, wrong signer, threshold, tampered bundle, wrong
  amount/digest/position, finite cap: the feat(economic): class 0x0029 AuthorizedIssuanceV1 — the missing source predicate #748 core suite, still green on
  the committed blob format.
• No raw bypass (mutation-controlled): neutralize the accepting gate and
  the named test goes red by actually crediting 1,000 units from air;
  restored green.
• TokenAuthority mechanism tests re-keyed to burn (which still carries the
  embedded witness) plus token_authority_does_not_gate_mint.

Stale text

Every "class 0x0029 is not written / does not exist yet" claim is corrected —
the route stub, the accepting-layer comments and errors, credit.rs's
"still reserved" doc, economic/mod.rs's "no encoder" doc, a fused variant
doc in issuance.rs, and the dead AdmissibleIssuancePolicy struct is
deleted.

Verification (exact gate commands, pinned 1.98.0)

workspace  --release   3925 passed / 0 failed across 72 suites, exit 0
node       --release   270 passed / 0 failed, exit 0
make lint              exit 0
production safety      exit 0