Add MCMC inversion mode alongside NA in TC1D (clean PR to develop) + Enhance erosion model (ero_type 2) to support up to 5 intervals

[gerardb-fr]

Clean follow-up to the earlier PR (#42).

• Does not edited sample_data.csv
• Does not add tc1d_original.py
• Targets develop as requested

Key changes:

• Adds batch_run_na() and batch_run_mcmc() functions
• Adds --inverse-mode flag in tc1d_cli.py
• Preserves existing TC1D structure and CLI compatibility
• Generates optional MCMC diagnostics (chains, corner, misfit)
  -- Added CLI options: --ero-option9 and --ero-option10
• Extended erosion rate calculation for up to 5 intervals (thickness + time)
• Updated total exhumation calculation to include ero_option9
• Applied constraints in MCMC and NA to prevent exceeding max exhumation
• Extended batch mode detection and output logging for new parameters
• Added bounds logic in ‘batch_run_na’ to handle negative erosion values (up to -15 km) using max_burial and max_exhumation constraints.
• Enforced cumulative erosion thickness to avoid total uplift above surface.
• Safeguarded temperature and pressure interpolation for depth < 0 (to avoid scipy interpolation errors).
• Updated MCMC log_prior constraints to support negative values for ero_option1, 3, 5, 7, 9
• Enforced dynamic upper/lower bounds for each interval based on cumulative exhumation and burial limits
• Introduced max_burial (default 15 km) as lower limit for allowed burial
• Rejected models with cumulative erosion < 0 km to avoid unrealistic above-surface placement
• Applied identical logic for both NA and MCMC to ensure consistent inversion behavior
• All changes clearly marked with '# BG:’
• Preserved full backward compatibility for previous 3-interval configurations

This enables testing of more complex, stepwise erosion histories in both forward and inversion modes.