Size swaps on free collateral and report refused pool draws on /status

[LandynDev]

Summary

Size swaps on the miner's free collateral, and tell the offering at once when the contract refuses a pool draw.

Motivation

Prod 2026-09-05 12:23 ET: a 1.98 TAO -> ARBUSDC swap passed the routed reserve pre-check, then finalize_reservation refused it with InsufficientCollateral. The off-chain purse is gross; the program gate is purse - reserved_collateral[hub]. The validator dropped the queue silently, so the offering saw none and waited out its 15 minute backstop.

Changes

• free_purse: backing_purse net of reserved_collateral[hub] (hub_reserved_collateral, same slot rule as hub_busy_until). Candidate building, the reserve pre-check and CLI quote/view size on it. Activation keeps the gross read, as vote_activate does.
• A refused finalize is kept per (miner, pair), published before the queue drop. Seam /status answers rejected with detail.reason and detail.users while no live reservation exists; the next request on that pool clears it; the status memo keys on a verdict epoch so no poll straddles a change. Memory only: after a restart the offering falls back to its backstop.
• Tests: net purse, zero floor, pre-v3.3 state, reserve refusal, verdict recorded and cleared, /status precedence.
• Version bump to 3.3.3.

Pairs with e35VenturaLabs/allways-access#188 (fail the seat at once on rejected). Either side deploys first.