chore!: clear deployment state and flag the fork as unaudited

[mfw78]

Nothing in this tree is deployed, and the artefacts still said otherwise.

• removes the legacy root networks.json (274 lines, 8 contracts x 8 chains). Those are upstream's addresses, for contracts this fork no longer matches after the generateOrder rename, typed errors, poll interface and proof-payload changes. Leaving the file invited them to be read as this fork's own deployments. When this fork does deploy, the canonical record is deployments/networks.json, landing in docs: monitoring-service terminology, verdict permanence, deployments manifest #41.
• dev/verify-contracts.sh was the file's only consumer. It now fails with a clear message instead of feeding null addresses into forge verify-contract.
• drops the README address table and states plainly that there are no deployments.
• reframes the audit list. It previously read "The above deployed contracts have been audited by" directly under the address table. Those audits cover upstream before this work, so leaving it unqualified alongside an unaudited warning would have been contradictory.
• adds a warning under the README title that the fork is unaudited, not deployed, and substantially changed.

BREAKING: networks.json is removed. Any consumer resolving addresses from it was resolving upstream deployments, not this fork's.

How to test

rg '0x[0-9a-fA-F]{40}' README.md   # no addresses left
test -f networks.json               # gone
./dev/verify-contracts.sh 1         # fails with the no-deployments message

Part of #1.