Fix count JSON readiness, find all scans, and format aliases

[Widthdom]

Summary

• Add command-specific --format aliases/validation for symbols, map, and inspect.
• Add explicit bounded find --all repo-wide scans with count scan summaries.
• Add count-only JSON readiness envelopes and mark partial/truncated counts as non-authoritative.

Validation

• dotnet build CodeIndex.sln -p:UseSharedCompilation=false
• dotnet run --project tools/CodeIndex.Changelog -- check
• Targeted issue/regression tests for Search output format aliases should be consistent across map, symbols, and inspect #3446, find should support explicit repo-wide scopes with bounded scan statistics #3560, and Count-only query JSON should include filters and authoritative-readiness signals #3566
• dotnet ./src/CodeIndex/bin/Debug/net8.0/cdidx.dll index . --quiet
• dotnet ./src/CodeIndex/bin/Debug/net8.0/cdidx.dll status --check --json
• dotnet test CodeIndex.sln --filter "FullyQualifiedName!~RunPublishedTrimmedCli_SerializesQueryJsonAndErrorJson" -p:UseSharedCompilation=false

Note: the unfiltered full test run is blocked locally by the existing missing .NETCore.App 10.0.8-servicing.26229.119 runtime for RunPublishedTrimmedCli_SerializesQueryJsonAndErrorJson.

Adversarial review

• Ran the required Codex adversarial review twice. The second round findings were fixed; per workflow, no third round was run without explicit user request.

Fixes #3446
Fixes #3560
Fixes #3566