esm_catalog: capture control-simulation reference & branch-off lineage (D1)

[siligam]

D1 asks for control-simulation reference and branch-off lineage (parent name/path, branch-off year, restart file used — see #1407). Currently not modeled at all in esm_catalog.

Good news: most of the data already exists in finished_config.yaml per component — ini_parent_exp_id, ini_parent_date, ini_parent_dir, restart_in_sources (confirmed against a real branched-off run on Albedo). No field exists yet for a broader "control simulation" reference though — would need a new runscript convention or an esm-tools schema addition, open question.

Planning to land the finished_config.yaml extraction in PR-A4 (#1489) and leave the STAC schema/extension part for a later PR once #1484 unblocks.

[siligam]

Validated against real experiments on Albedo (/albedo/work/user/pgierz/SciComp/Tutorials/AWIESM_Basics/experiments/) — basic-001 (cold start) and branchoff-002 (branched off basic-002).

Correction to the implementation pushed for this issue: the original commit derived parent lineage by parsing config[component]["prev_run_config_file"]. That field never appears in branchoff-002's finished_config.yaml. The real, primary mechanism AWIESM runscripts actually populate is:

echam:
  lresume: true
  ini_parent_exp_id: basic-002
  ini_parent_date: '1854-12-31'
  ini_parent_dir: /albedo/.../experiments/basic-002/restart/echam/

prev_run_config_file is a separate, opt-in mechanism (see esm_runscripts.prev_run's user_error message) that this real experiment doesn't use. Fixed extract_stac_metadata() to prefer ini_parent_exp_id/ini_parent_date/ini_parent_dir when present, falling back to prev_run_config_file parsing otherwise. restart_in_sources (the restart-file dict) was independently confirmed correct — branchoff-002's first run period's restart_in_sources does point at basic-002's restart files, exactly matching D1's "initial condition (restart file used from previous simulation)".

Pushed to both origin/esm-tools-plus/simcat/collapsed-collections and origin/esm-catalog/pr-a4-integration (#1489).