Your premise is a fascinating and provocative geopolitical chessboard. Let's think outside the box, taking your core assumptions—pragmatism over moralism, a coalition of regional powers, and the exclusion of traditional Western mediators—as the starting point.

The Grand Strategy: "The Persian Gulf Stability and Sovereignty Pact"

The goal isn't a Western-style revolution, but a managed, irreversible transition from a theocratic revolutionary state to a secular, functional nation-state. The core insight: you must give every key actor a stake in the outcome, especially those who fear a chaotic Iran most.

1. The Unconventional Coalition & Their "Carrots":

• Saudi Arabia: Their carrot is security and economic dominance. The deal includes a permanent, verifiable Iranian commitment to never pursue nuclear weapons and to end all support for proxies in Arab states (Houthis, Shia militias in Iraq/Syria). In return, Saudi Arabia invests heavily in Iranian oil/gas infrastructure and agrees to a joint OPEC+ strategy managed by Riyadh and Tehran. This makes them co-custodians of the global energy market.
• Turkey: Their carrot is economic and strategic depth. Turkey gets to be the principal logistics and trade corridor for a reborn Iran, with massive infrastructure projects (pipelines, railways, highways) connecting Europe to Central Asia via Turkey and Iran. Ankara also gets a seat at the table on Kurdish issues, with a cooperative Iran.
• Oman: Their carrot is elevated status and profit. Oman becomes the neutral diplomatic and financial hub for the entire process—the "Geneva of the Gulf." All secret talks, financial transactions, and monitoring groups are based in Muscat. This brings immense prestige and revenue.
• China: Their carrot is stability and resources. China signs a 50-year "Comprehensive Development and Purchase Agreement" with the future Iranian state. China gets first-right-of-refusal on oil/gas at a fixed discount, and in return, provides the massive infrastructure investment (ports, railways, 5G networks) for Iran's reconstruction—but only after the transition deal is signed. This gives China a powerful incentive to pressure Tehran's elite toward a deal.
• Russia (a potential addition you didn't mention, but crucial): Their carrot is managed decline of influence. Offer Russia a guaranteed role in Iran's civilian nuclear energy program and a joint venture in Caspian Sea resources. The unspoken deal: you can keep some influence, but you must stop using Iran as a spoiler. In return, the West tacitly accepts some Russian spheres of influence elsewhere.

2. The "Stick" for Tehran's Elite: A Golden Bridge and a Trap Door. You don't attack the Islamic Republic; you offer its elite a golden exit.

• The "National Wealth Fund" Amnesty: Create an internationally managed fund. All current elite (IRGC commanders, bonyad leaders, clerics with commercial empires) can deposit their illicit wealth into this fund with no questions asked and full amnesty from future prosecution. The fund is then invested, and they receive annual dividends for life. This legally launders their wealth and gives them a permanent income stream—but only if the transition proceeds.
• The "Islamic Cultural Guardianship" Clause: To placate fundamentalists and conservative clerics, the new constitution designates Qom and Mashhad as special autonomous religious-cultural zones, where Sharia law can prevail locally. This creates a " Vatican City" solution, allowing the theological core to remain, while the nation-state operates on secular civil law.

3. Why Not the EU/Israel/Qatar? The Pragmatic Cut-Out.

• EU: As you stated, their process is often slow, moralistic, and consensus-driven. They would insist on immediate human rights benchmarks that could derail the delicate early stages. They are kept informed but not in the room. Their role comes later: providing technical expertise and a massive reconstruction market after stability is secured.
• Israel: Their inclusion is a deal-killer from the start. Iran's regime, and even many secular nationalists, cannot be seen negotiating their future alongside Israel. Israel's security concerns are addressed bilaterally and secretly with the U.S. and Saudi Arabia, with guarantees on Iranian capabilities. Their public exclusion is essential for Iranian domestic legitimacy.
• Qatar: They have cultivated ties with all sides (Iran, the West, Islamists) to maximize their influence as a mediator. A stable, powerful Iran reduces Qatar's unique value. They benefit from a certain level of managed tension. They are too invested in the status quo to be a force for transformative change.

4. The "Trump" Mechanism: The Ultimate Reality Show Deal. This is where Trump's unique, norm-breaking style could be weaponized.

• The "Summit of the Decade": Trump, leveraging his relationships with MBS and Erdogan, convenes a sudden, shocking summit in Oman: the leaders of Saudi Arabia, Turkey, Oman, China, and Iran. No prior leaks, no lower-level talks. The message: "This is the table. History is made here. Be on the right side of it."
• The "Art of the Grand Gesture": Announce a "Marshall Plan for Persia" funded by the coalition, with breathtaking scale. Frame it not as a defeat for Iran, but as its "return to greatness" as a sovereign, modern nation, free from sanctions and isolation.
• Leverage U.S. Power Asymmetrically: Offer an immediate, total lifting of all U.S. sanctions via Executive Order upon signing of the framework. Simultaneously, threaten a devastating "secondary sanctions" regime on any entity worldwide doing business with Iran if they walk away—a weapon only the U.S. can wield.

The Unconventional Core: This plan bypasses democracy and human rights as starting points. It is a cold, realpolitik transaction that buys out the corrupt elite, bribes the neighbors with profit and security, and uses China's hunger for resources as a lever. Stability and secular functionality are the primary goals; freedom and democracy are hoped-for long-term byproducts of opening the country. The Nobel Prize would be for ending a 40-year cold war and fundamentally realigning the Middle East, not for creating a Jeffersonian democracy overnight. It's brutal, amoral in its mechanics, but potentially transformative in its outcome.