fix: on-chain upgrade name 3.0.0 -> v3.0.0 (match v2.x naming standard)

[Ninjaxan]

On-chain upgrade name: 3.0.0 → v3.0.0

Every prior on-chain upgrade name on passage-2 carries the v prefix — the handler Name constants are v2.2.0, v2.4.0, v2.5.0, v2.6.0. The 3.0.0 handler shipped without it. This one-line fix restores the convention so the upgrade name is v3.0.0.

app/upgrades/v3.0.0/upgrade.go:  const Name = "3.0.0"  ->  const Name = "v3.0.0"

(Log strings updated too; the directory/package were already v3.0.0/v3_0_0.)

Validated

Re-ran the real-state fork test on an exported passage-2 snapshot with the v3.0.0 name: gov prop v3.0.0 → halt at the upgrade height → handler v3.0.0 fires → all module migrations → v3.0.0 upgrade: complete, blocks produced past the height, no panics.

Heads-up — this changes the binary, so it needs a re-release

The on-chain name is baked into the binary's handler and must match the gov proposal. The current v3.0.0 release binary has handler name 3.0.0. After this merges, please re-cut the v3.0.0 release (the existing one is hours old and not yet deployed by any validator) so the tag, the on-chain name, and the upgrade doc all read v3.0.0. The new gov proposal will use name v3.0.0 and point --upgrade-info at the re-cut binary.

(The already-submitted proposal #21 used the old name 3.0.0; it can't be cancelled on SDK 0.45, so it will be left to fail on quorum — deposit returns — and superseded by the corrected v3.0.0 proposal.)