### Description
1. Fixing issues identified by similarity checker
2. Fix the corresponding sql unit tests
3. Fix JSTests failure due to above changes
4. Fix corresponding C# test failure
----
#### AI description (iteration 1)
#### PR Classification
This pull request is a code cleanup that standardizes and improves error message wording across the codebase.
#### PR Summary
The changes update error messages throughout the repository to provide clearer, more consistent, and more detailed feedback when operations fail.
- Updates in geospatial operator files (e.g. in `$geoNear`, `$near`, `$nearSphere`) replace informal phrasing with precise messages.
- Numerous error messages in aggregation and projection test files have been reworded for consistent phrasing
<!-- GitOpsUserAgent=GitOps.Apps.Server.pullrequestcopilot -->
### Does this PR have any customer impact?
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
### Are you introducing any new config? If yes, do you have tests with and without them being set?
### ChangeLog (Refer [Template](../oss/CHANGELOG.md))
### Description
draft
----
#### AI description (iteration 1)
#### PR Classification
Bug fix: This PR revises error messages and inline comments to improve clarity and consistency across the code and test outputs.
#### PR Summary
The changes refactor and update a large number of error messages across various modules—ranging from aggregation and update operators to geospatial, schema validation, and command handling—to provide more precise diagnostic feedback.
- **Tests (e.g. in `tests/expected/...
<!-- GitOpsUserAgent=GitOps.Apps.Server.pullrequestcopilot -->
### Does this PR have any customer impact?
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
### Are you introducing any new config? If yes, do you have tests with and without them being set?
### ChangeLog (Refer [Template](../oss/CHANGELOG.md))
### Description
update errmsg
----
#### AI description (iteration 1)
#### PR Classification
This pull request focuses on updating and standardizing error messages across various operators, aggregation stages, and test expectation files.
#### PR Summary
The changes reword error messages throughout the codebase and test outputs to provide clearer, more consistent, and more informative feedback for users. Key updates include:
- **`/oss/internal/pg_documentdb_distributed/src/test/regress/expected/*.out`** – Revised expected error outputs for aggregation, update, and geospatial tests to use clearer phrasing (e.g., for `$merge`, `$pop`, `$indexOfArray`, and `$geoNear`).
- **Core operator files (e.g., `bson_aggregation_output_pipeline.c`, `bson_expression_arithmetic_operators.c`, `bson_expression_conditional_operators.c`)** – Updated error message texts to explicitly state operator requirements and types.
- **Geospatial and vector modules (e.g., files under `bson_geojson_utils.c`, `bson_geospatial_*`, and vector search/index configuration files)** – Standardized validations and error reporting for GeoJSON, CRS, and vector search parameters.
- **Additional modules (e.g., collection view creation and user management files)** – Improved error handling messages to better guide users on input misconfigurations.
<!-- GitOpsUserAgent=GitOps.Apps.Server.pullrequestcopilot -->
### Does this PR have any customer impact?
No
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Other
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### ChangeLog (Refer [Template](../oss/CHANGELOG.md))
### Description
Aligning to contributing guideline for geospatial module
----
#### AI description (iteration 1)
#### PR Classification
This pull request performs a code cleanup in the geospatial module to improve clarity and consistency across comments, error messages, and test outputs.
#### PR Summary
The changes refine inline documentation and output messages to accurately describe the intended behavior of geospatial operators—especially for the $geoWithin operator—and standardize legacy processing with Postgis expectations.
### Does this PR have any customer impact?
No
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Feature
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### ChangeLog (Refer [Template](../oss/CHANGELOG.md))
- Support top level let variables in $geoNear stage
### Description
Support top level let variables in $geoNear stage
- Today there are 2 scenarios where `let` is used with $geoNear
1- `top level`: Any `let` provided in the top level command such as `aggregate`, the variables used in geonear spec should result into a `constant`, so we evaluate and rewrite the geoNear spec before parsing it to replace any expressions/let variables from top level let.
2- `nested let`: This scenario occurs with lookup pipeline and let is a combination of top level let and lookup let, this case is not optimized in this PR and will still return in error
----
#### AI description (iteration 1)
#### PR Classification
New feature
#### PR Summary
This pull request adds support for top-level `let` expressions within the `$geoNear` stage in aggregation pipelines.
- `oss/pg_documentdb/src/aggregation/bson_aggregation_pipeline.c`: Added logic to handle `let` expressions by updating the `$geoNear` specification if a `CONST let` expression is present in the context.
<!-- GitOpsUserAgent=GitOps.Apps.Server.pullrequestcopilot -->
### Does this PR have any customer impact?
No
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Refactoring
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
Remove helio references from documentdb
Remove helio references from documentdb_distributed
----
#### AI description (iteration 1)
#### PR Classification
Code cleanup
#### PR Summary
This pull request removes references to "helio" and replaces them with "documentdb" in the sources of `documentdb` and `documentdb_distributed`.
- `metadata_cache.h` and `metadata_cache.c`: Replaced "Helio" with "DocumentDB" in variable names and function names.
- `pgmongo.c`: Updated include statements and function calls to use "documentdb" instead of "helio".
- `planner.c`: Updated planner function and related calls to use "DocumentDBApiPlanner".
- Moved several header files from `helio_*` to `documentdb_*` naming convention without code changes.
- `commands_common.c` and `create_indexes.c`: Updated function calls and variable names to use "DocumentDB" instead of "Helio".
### Does this PR have any customer impact?
No
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Refactoring
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
Remove helio from file name
Remove helio references from source content except schema reference
Start local documentdb server with the documentdb extension
Regression tests using the documentdb extension
----
#### AI description (iteration 1)
#### PR Classification
Code cleanup
#### PR Summary
This pull request removes references to "helio" from the `documentdb_core` source code.
- `scripts/utils.sh`: Renamed variables from `preloadExtensions` to `preloadLibraries`.
- `pg_documentdb_core/include/utils/error_utils.h`: Updated function and macro names to replace "Helio" with "DocumentDB".
- `pg_documentdb_core/include/io/helio_bson_core.h` and `pg_documentdb_core/include/query/helio_bson_compare.h`: Moved to `pg_documentdb_core/include/io/bson_core.h` and `pg_documentdb_core/include/query/bson_compare.h`.
- `pg_documentdb_core/src/collation/collation.c` and `pg_documentdb_core/src/io/pgbson.c`: Replaced error codes and messages to use "DocumentDB" instead of "Helio".
- `scripts/validate_helio_extension_state.sh`: Added exceptions for certain files to skip validation for "helio" references.
### Does this PR have any customer impact?
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
### Are you introducing any new config? If yes, do you have tests with and without them being set?
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
[OSS] remove dependencies on helio errors
### Does this PR have any customer impact?
No
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Refactor
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
Move source files under new directory.
----
#### AI description (iteration 1)
#### PR Classification
Code reorganization
#### PR Summary
This pull request moves the `helio_api` and `helio_distributed` sources under the `documentdb` directory, updating references and initialization logic accordingly.
- Added `pg_documentdb.c` for initializing the `pg_documentdb` extension.
- Added `documentdb_distributed.c` for initializing the `pg_documentdb_distributed` extension.
- Updated `validate_helio_extension_state.sh` to include new checks for `documentdb`.
- Moved `helio_api_extension_version.c` to `documentdb_extension_version.c` without code changes.
- Updated various `Makefile` configurations to reflect the new directory structure and dependencies.
Jinrui Zhang
Xing Fan
Duan Pei
Deepak Bisht
Zinan Ren
Shuai Tian
Vinod Sridharan