Add range constraints to model inputs and throw error for out of range inputs

[dlebauer]

Increase validation of inputs (especially .param and .clim), by enforcing bounds, including:

• many parameters have a lower bound at 0,
  • e.g. first order rate parameters (k values)
  • precip, irrigation, events
• most or all fraction parameters should be bound [0,1] <-- exceptions to be confirmed
  • variables with 'frac', in name
  • variables with 'allocation' in name, but note:
    • ensureAllocation() checks each is <1 and all sum to 1, but not that individual terms are non-negative
    • coarseRootAllocation is computed internally and out of scope for this issue
  • frozenSoilEff, frozenSoilFolREff
  • Clarify nVolatilizationFrac and nLeachingFrac units. These are fraction per day (day^-1), but state.h calls them unitless fractions
• anaerobicTransExp should be bound at >=1 (per docs, empirically)

Error if inputs are out of bounds. Current behavior mixes clipping and errors, prefer errors to avoid making upstream errors invisible.

Out of scope:

• physics/biogeochem-informed bounds except where part of documented model structure (anaerobicTransExp)
• bounds on internal variables and outputs. For some of these we could use very wide sanity-check bounds like those in https://betydb.org/api/v1/variables.

[ayushman1210]

Based on the issue description, the following changes are needed to enforce bounds on inputs (primarily .param and .clim files) and error on out-of-bounds values instead of clipping. This focuses on runtime parameters, climate data, and event inputs, while excluding physics-informed bounds beyond anaerobicTransExp and bounds on internal variables/outputs.

CHANGES

1. Parameter Bounds (.param files)

• Add minVal/maxVal to OneModelParam struct and initializeOneModelParam() function.
• Enforce bounds in readModelParams(): error and exit if value < minVal or > maxVal.
• Update all initializeOneModelParam() calls in sipnet.c with specific bounds:
  =0 for rates/masses (e.g., plantWoodInit, aMax, baseVegResp, etc.).
  [0,1] for fractions (e.g., aMaxFrac, fracLeafFall, leafAllocation, etc.).
  anaerobicTransExp >=1.
• Clarify nVolatilizationFrac/nLeachingFrac units as day^-1 in state.h.
• Enhance ensureAllocation() to check individual allocations >=0.

2. Climate Bounds (.clim files)

• In readClimData(), check precip >=0, par >=0, vpd/vpdSoil/vPress/wspd >=0 after assignment; error if violated.

3. Event Bounds (events.in files)

• In createEventNode(), add checks: IRRIGATION amountAdded >=0; FERTILIZATION orgN/orgC/minN >=0; PLANTING pools >=0; TILLAGE tillageEffect [0,1] or >=0.

4. Testing/Docs

• Add tests for out-of-bounds errors.
• Update parameters.md and CHANGELOG.md.

@dlebauer i would like to work on this issue
thanks !!