gdal_config_sitrep(): Configuration Situational Report

The view tier of the GDAL configuration system (#8): a live, provenance-attributed report of the effective GDAL configuration landscape. Situational awareness is a core goal of the package - large GDAL workloads are opaque by default, and understanding "what is in effect and who set it" currently requires manual trial-and-error archaeology.

Scope (initial)

gdal_config_sitrep() returns a classed gdal_config_sitrep object (cli print, tibble::as_tibble() method) reporting, per key:

• effective - live value from gdalraster::get_config_option() (GDAL is the single source of truth; nothing mirrored).
• envvar - value present in the process environment.
• set - value pinned by this package (the active gdal_config).
• source - best-effort provenance: gdalvector | envvar | config_file | external (another package / direct gdalraster call) | unset.

Coverage: keys pinned by the package, GDAL-relevant envvars (prefix scan), config-file [configoptions] entries, plus a probe of the full known-option universe (runtime VSI metadata + driver metadata + curated core list) so externally set in-memory values for any documented key are discovered. Secret-bearing values are redacted by key pattern in all printed output.

Additional sections:

• discovered GDAL config file (path + parsed contents; see [Feature]: GDAL Configuration File (gdalrc) I/O #13),
• VSI path-bound options per prefix (redacted),
• an at_load baseline sitrep stashed at package load - the state of the world as gdalvector found it, enabling "what changed since load" diffing.

Follow-up scope

• Per-prefix credential resolution view: for each VSI prefix in use, report what is bound at the path tier, what would resolve from the global chain (and from which rung: memory/envvar/file), which credential envvars are present, whether out-of-band credential sources exist (~/.aws/credentials + AWS_PROFILE, GOOGLE_APPLICATION_CREDENTIALS, Azure connection strings, IMDS), and what gdalrc [credentials] declares. Answers "who will authenticate this request and why" without CPL_CURL_VERBOSE archaeology.
• gdal_config_diff() against the at_load baseline (or between two sitreps).
• Integration with the package-wide gdal_sitrep() ([Feature]: Polish gdal_sitrep() #10) as its configuration section.

Related

#8 (parent design), #13 (config file), #10 (gdal_sitrep polish)