Bugfixes: Transmission FOM, stress hour reporting, planned transmission

[patrickbrown4]

Summary

This PR fixes three bugs:

1. Interzonal transmission FOM costs were high by a factor of 2
2. A couple operational metrics for stress periods were off for years before the final solve year
3. A couple planned transmission lines were being dropped when using non-default yearsteps

Technical details

Implementation notes

1. Transmission FOM: Divided by 2 in both the objective function and output reporting
2. Missing stress hours: Added a new hours_t(allh,t) parameter (like h_t(allh,t) to keep track of changing stress period hour weights over model years
3. Missing off-year lines: Moved lines added between model years to the next modeled year in transmission.py

Additional changes

• Added a new checkbox to the PR template, reminding the author to make sure new objective-function parameters are added to the objective_function_params.yaml used in check_inputs.py
• Removed the sitemap.h5 and sc_point_gid_old2new.csv files, which are out of date (thanks @sriharisundar for noticing)

Issues resolved

• CAPTRAN_ENERGY terms in objective function high by 2x #127
• report.gms: Fix hours for pre-final-year stress periods #146

Validation, testing, and comparison report(s)

• The SunZia line now shows up between NM and AZ when using 5-year steps: results-v20260716_bugsM0_AZNM,v20260716_bugsM1_AZNM.pptx
• Here's the USA_defaults comparison: results-v20260716_mainK1_USA_defaults,v20260716_bugsK1_USA_defaults.pptx. Changes are dominated by fixing the transmission FOM cost:
  • Interzonal transmission capacity increases by ~20 TW-miles in 2050 (~13%)
  • NPV of system cost falls by ~$150B (~2.1%)
  • Generation impacts aren't too big; ~18 GW more wind, with reductions in solar, gas, and storage

Checklist for author

Details to double-check

• Charge code provided to reviewers
• Included comparison reports for appropriate test cases
• Code formatting standardized
• Reusable functions used where possible instead of copy/pasted code

General information to guide review

• Zero impact on results of default case
• No large data file(s) added/modified
• No substantive impact on runtime for full-US reference case
• No substantive impact on folder size for full-US reference case
• No change to process flow (runreeds.py, reeds/core/solve/solve.py)
• No change to code organization
• No change to package requirements (environment.yml or Project.toml)

Did you use LLM tools (chatbot or copilot) in the preparation of this PR? If so, describe how

Nope