Teleporting food in is pretty much right out. You can't build a teleport logistics network in a day. There's likely no place in Golarion - and certainly no place within his teleport distance - that Salgar Irevotnin could roll up and buy the 3,229 pounds of flour (65 gp) it'd take to feed Korvosa for a day, all packaged for a literal hundred castings of shrink object (impossible at any price, but in theory 15,000 gp) or, more reasonably, packaged to be carried by a 90 gp team of 30 gp ponies each buffed with bull's strength for six teleports and three round trips.

And if the Academae Deans (plural because Salgar alone couldn't can't cast six 5th-circle spells) were hypothetically being paid for their hypothetical services the listed price is something like 3,000 gp for the teleports and 1,350 for the bull's strength. All to transport 65 gp in flour so Korvosa could feast on wheatpaste glue.

Create food and water is a third-circle cleric spell that feeds 15 people per casting.

Absent any repeating spell traps, that's not really going to put a dent in the problem.

But do not despair:

Mage's Magnificent Mansion

School conjuration (creation); Level sorcerer/wizard 7

You conjure up an extra-dimensional dwelling that has a single entrance on the plane from which the spell was cast. The entry point looks like a faint shimmering in the air that is 4 feet wide and 8 feet high. Only those you designate may enter the mansion, and the portal is shut and made invisible behind you when you enter. You may open it again from your own side at will. Once observers have passed beyond the entrance, they are in a magnificent foyer with numerous chambers beyond. The atmosphere is clean, fresh, and warm.

You can create any floor plan you desire to the limit of the spell’s effect. The place is furnished and contains sufficient foodstuffs to serve a nine-course banquet to a dozen people per caster level. A staff of near-transparent servants (as many as two per caster level), liveried and obedient, wait upon all who enter.

Banquets are for celebrations, so let's split nine courses between three people and call them square meals instead.

For 910 gp you can hire a 13th level wizard to make 234 gp worth of foodstuffs.

That isn't typically a winning trade, nor at all sustainable in the long term, but the Korvosans in the Vault can't eat gold. A casting of Mage's Magnificent Mansion can feed 468 people.

Or, assuming that no one will starve on one "Meal, good" a day, 1404 people. Korvosa has 3,229 people left, so it'd only take four castings of the spell. 3640 gp.

Not every town or village has a spellcaster of sufficient level to cast any spell. In general, you must travel to a small town (or larger settlement) to be reasonably assured of finding a spellcaster capable of casting 1st-level spells, a large town for 2nd-level spells, a small city for 3rd- or 4thlevel spells, a large city for 5th- or 6th-level spells, and a metropolis for 7th- or 8th-level spells. Even a metropolis isn’t guaranteed to have a local spellcaster able to cast 9th-level spells.

With a population of 18,486, Korvosa was a large city.

But despite its unfavorable location in provincial Varisia - more than a month by ship from Westcrown and too distant from Absalom for a 5th-circle wizard to cross in one teleport - Korvosa has long punched above its weight when it comes to what arcane magic is for sale. Volshyenek opened his Academae two hundred and thirty years ago, when Korvosa was even smaller than circa 4706, and from that fiefdom peddled 9th-circle wishes for the next hundred and thirty four years.

And then Aroden died in 4606, and Golarion was devastated by a year without a harvest. There was civil unrest, and thousands of exiled or dissatisfied Korvosans fled to Magnimar. The Shoanti, hunters and herders less effected by the ruined harvest, saw weakness in the Chellish colonies that they hadn't in a hundred years. At some point in chaotic 4607 Lord Volshyenek Ornelos was murdered by a legion of invading devils from out of Hell. Cheliax had its own problems, and had no attention to spare a province six weeks by sail over turbulent seas.

For the hundred years since 4607, little Korvosa has been without a 9th-circle arcane caster. They've usually been without an 8th-circle wizard, and for long stretches they've gone without 7th-circle arcane spells too. But the institutions that Volshyenek built had deep roots; the Academae proved a tenacious and perennial plant, attracting wizards of power and raising wizards to power.

The mightiest among them in the current day was the Headmaster of the Academy himself, Heir to the Eternal Lord, Lord Toff Ornelos, who alone of Korvosa's permanent residents could cast 7th-circle wizard spells and 8th.

With a population of 3,229, Korvosa is a large town. Supposedly it should lack 3rd-circle spells.

This is not the case.

Sure, many of Korvosa's wizards died last night. Death ward isn't a wizard spell, and wizards aren't known for their Strength scores. Most were weak to begin with and suffered age penalties, which begin at 35 and intensify at 53 and 70. Wizards that survived their first six seconds after being jumped by a shadow seldom made it through the next six.

Most of the spells that Korvosa's wizards prepared, not expecting a desperate fight in the middle of the night against incorporeal undead, were in the event pretty useless.

The median Korvosan wizard gets three or fewer spells per day. They have jobs to work; if a first-level wizard prepped combat spells with no plan to ever use them, who would pay them? And for what?

The fraction of Korvosa's wizards with combat spells don't fair much better - sleep will save you from a mugger in a dark ally, black tentacles will do much the same and with far more style, and neither will have any effect on a shadow.

But expeditious retreat, invisibility, beast shape I, dimension door? None guarantee survival, and not everyone had such a spell prepared. But for Korvosa's 3rd-circles, the odds weren't terrible.

And the teleport-capable Deans of the Academae were only ever in as much danger as they chose to be.

The Pathfinder Society is an adventurer's guild based out of Absalom, the city at the center of the world.

 

Not, like, the literal center of the world, beneath Orv. The literal center of the world is one of the places no Pathfinder has chronicled, a blank space on the map marked "Here there be Rovagugs."

 

Absalom is at the center of the world in a different sense, in the sense that it's the biggest city in the Inner Sea, which is a broader and more relevant superlative than it might sound.

 

Pathfinders have a bit of a reputation, in Golarion. They're said to know far more than they should, to have a knack for entrances and exits, to get away with things that by rights they shouldn't. And they're known for tolerating eclecticism, and overwhelming power. People say that Pathfinders are just built different.

Toff Ornelos hired them to fight off the shadows and save Korvosa. It's anyone's guess whether, with Korvosa in ruins, the man will pay up.

They've been taking on other jobs, and will take on more in the morning. People are still teleporting in, Aram thinks it'll be days yet before Korvosa hits Peak Adventurer. There's a lot of profitable work to do and the shadows enforce a slow pace doing them; death ward is scarce and lasts less than ten minutes, when Korvosa takes more than 20 minutes to cross unenhanced if you're just trying to cross it. The Pathfinders will have to set up forward camps if they want to get anything done.

The Academae Master is alive and well. Aram heard through his telepathic bond that an Absalom cleric reached him through sending. The headmaster says he'll return to Korvosa in the morning; it seems likely that he ran out of teleports somewhere and has to spend the night. Toff Ornelos has a truly freakish number of teleports, it's one of his tricks, but probably he doesn't have a literally infinite amount.