[VickyXAI]

Closes the known gap noted in 3.24.8 (and the P2 from the #90 review).

Problem

The SDK reads the channel on-chain only before a top-up. A reclaimed channel (PayAI closes channels idle for 72h) whose local record still has deposit to spare gets an authorization signed into it on every call. The gateway rejects it at verify and answers with a plain 402 with no receipt (blockrun-sol src/lib/batch/payment.ts, fail()). The SDK classifies that as not_charged / payment_required and pays exact, so every later call pays exact (1.5–4.5×) until the channel file is deleted by hand.

Change

• payWith: when the first send of an authorization is refused with a plain 402 (payment_required, no admission cooldown), the new recheckRefusedChannel() reads that channel:
  • open, and this wallet's → kept; the next call pays into it again
  • closing / closed / foreign at finalized → channel_unusable re-read (closed → record dropped)
  • gone at finalized and at confirmed → queueReclaimed(), the anchored wait from fix(batch): drop a reclaimed channel on the SDK's own chain evidence, not the 402's openSlot #90, now shared with prepareTopUp: exact for about 2 minutes, then the record is dropped and the next call opens a fresh channel
  • only at confirmed (not finalized yet) → kept
• resync() runs right away, so a process that makes one call per run still finishes the wait.
• The scheme rewrites the record without reclaimAnchorHeight while it builds and settles a payment. So buildPayment() reads the saved anchor first and carries it on SentPayment.reclaimAnchor. A test caught this: without it, every short-lived run started a new wait.
• Best effort: a failed read changes nothing, the call already pays exact, and the next refusal checks again. Admission refusals, 429s and deposits keep their existing paths.

Tests

• A refused reclaimed channel pays exact during the wait, nothing is signed into it, and it reopens at +301 blocks. One getBlockHeight.
• A process that makes one call per run still drops the channel, using the saved anchor.
• A live channel refused for another reason is kept and paid into again, with no resync and no anchor.
• A channel the finalized chain shows closed is dropped right away (no wait).
• Three of the four fail on main. npm test: 954 passed, 12 skipped. Build, lint and typecheck are clean. grep -c router-core dist/index.d.ts → 0.

Docs: docs/solana-batch.md, CLAUDE.md batch section, CHANGELOG (Unreleased).