You need to gather evidence that your partner moved into the unit at the same time you did, despite not being named on the lease.
Pay the rent. That’s the best single piece of advice I can give to tenants. You’d be surprised at how many landlord issues disappear when you pay the rent.
Your one-year lease guarantees your rent for one year, not 11 months. This is even true in Bakersfield and Yuba City!
Like the issue of soft-story retrofits, the San Francisco capital improvements Ordinance and Rules are complicated and dense.
The landlord cannot increase your rent because you are an original tenant on the lease even if the girlfriend is moving.
Given the facts as you relate them, you shouldn’t have any problem “moving” to Los Angeles to accept a temporary contract job.
The landlord would argue that you are not an original occupant and, despite the fact that you paid rent directly to her agent, she did not waive his right to increase the rent.