feat: expose timing of planning in the report

[alepane21]

We want to expose query planning time to make easier and more precise to track query planner's performance regressions.

Summary by CodeRabbit

• New Features

  • Query plan results now include per-operation timing metrics (parse, normalize, validate, plan, post-process) aggregated per file and included in result objects — timings are present for both successes and failures.

• Tests

  • Tests and benchmarks updated to handle the new timing data and to compare structured plan results rather than raw JSON strings.

Checklist

• [ ] I have discussed my proposed changes in an issue and have received approval to proceed.
• [ ] I have followed the coding standards of the project.
• [ ] Tests or benchmarks have been added or updated.
• [ ] Documentation has been updated on https://github.com/wundergraph/cosmo-docs.
• [ ] I have read the Contributors Guide.

[coderabbitai[bot]]

Walkthrough

Instruments the planning pipeline with per-operation timing via a new public OperationTimes type; updates planner function signatures to return and propagate timing data through parse, normalize, validate, and plan phases (including error paths); exposes per-result timings in the plan generator and adjusts tests/benchmarks.

Changes

Cohort / File(s)	Summary
Core Planning Instrumentation router/core/plan_generator.go	Adds public OperationTimes (ParseTime, NormalizeTime, ValidateTime, PlanTime) with TotalTime() and Merge(). Updates PlanOperation, ParseAndPrepareOperation, PrepareOperation, and PlanPreparedOperation signatures to return OperationTimes; measures and accumulates timings around each phase and returns timings on success and error paths.
Planner Tests & Benchmarks router/core/plan_generator_test.go, router/internal/planningbenchmark/benchmark_test.go	Updates call sites to handle the additional OperationTimes return value from ParseAndPrepareOperation and PlanPreparedOperation (captured or ignored), preserving existing control flow and error handling.
Plan Generator Result & Generator router/pkg/plan_generator/plan_generator.go	Adds Timings core.OperationTimes to QueryPlanResult and populates it from Planner.PlanOperation so per-file timing data is included in results.
Plan Generator Tests Refactor router/pkg/plan_generator/plan_generator_test.go	Replaces raw JSON string equality checks with unmarshalling into QueryPlanResults and per-entry comparisons of Plan, Error, and Warning; minor import formatting change.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

• Verify that OperationTimes values are correctly captured, merged, and returned on all success and error paths in router/core/plan_generator.go.
• Confirm QueryPlanResult.Timings is populated consistently and that JSON marshaling still behaves as expected.
• Check updated tests/benchmarks properly ignore or validate timing data where intended.

Possibly related PRs

• wundergraph/cosmo#2236 — Related signature changes to Planner.PlanOperation (adds outputFormat) that overlap with this PR's signature adjustments.
• wundergraph/cosmo#2303 — Refactors the planning pipeline functions (ParseAndPrepareOperation, PrepareOperation, PlanPreparedOperation) which this PR further augments to propagate timing data.

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'feat: expose timing of planning in the report' directly and clearly describes the main change: adding timing information to planning reports for tracking performance.

✨ Finishing touches

• [ ] 📝 Generate docstrings

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[github-actions[bot]]

Router-nonroot image scan passed

:white_check_mark: No security vulnerabilities found in image:

ghcr.io/wundergraph/cosmo/router:sha-1f43bba1fe504a2709bc39544e26508f95949d2c-nonroot

[github-actions[bot]]

This PR was marked stale due to lack of activity. It will be closed in 14 days.