Update disturbance handling for harvest intensity classes

[erin-glen]

Motivation

• Disturbance raster coding changed to split harvest into four intensity bins (1–4) while keeping 5=insect/disease and 10=fire, so the processing and emissions logic must reflect that disaggregation.
• Emission factor lookup table now includes per-bin harvest factors and outputs must report area and flux per harvest intensity class.

Description

• Updated disturbanceLookup in lookups.py to map codes 1–4 to harvest_0_25_HA, harvest_25_50_HA, harvest_50_75_HA, and harvest_75_100_HA and kept 5/10 for insects/fire.
• In funcs.py adjusted disturbance tabulation to ensure the new harvest columns exist, refactored NA filling to generically handle all disturbance columns, and updated undisturbed_HA calculation to subtract the four harvest buckets.
• Extended merge_age_factors to read four harvest emission factor columns and updated calculate_forest_removals_and_emissions to compute annual emissions for each harvest intensity bucket (Annual_Emissions_Harvest_*_CO2).
• Propagated the new harvest buckets through area/flux mappings and summaries (calculate_area, calculate_ghg_flux, summarize_ghg), and included the new columns in the rounding/output logic in save_results.
• Adjusted recategorization cleanup in analysis_core.py to zero out the four harvest columns when recategorizing fire records.

Testing

• No automated tests were run for this change; recommend running the project's unit and integration tests and a full analysis run to validate outputs and CSV reports include the new harvest buckets.

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Codex Task