fix(errors): use resource not found over input validation for missing resources

[Hweinstock]

Problem

The refactor branch distinguishes malformed input (InputValidationError) from well-formed input naming an absent resource (ResourceNotFoundError):

Ex. already throws ResourceNotFoundError for lookup misses (e.g.

agentcore-cli/src/core/project/manager.tsx

Line 573 in 0caec7f

throw new ResourceNotFoundError(

,

agentcore-cli/src/core/project/manager.tsx

Line 586 in 0caec7f

throw new ResourceNotFoundError(

), but several other paths still throw plain InputValidationError for the same "named
entity absent" case

The language is also inconsistent across multiple places.

Solution

• migrate existing cases.

Verification

• test-pass, messages updated

[agentcore-devx-automation]

Claude Security Review: no high-confidence findings. (run)

[agentcore-devx-automation]

AgentCore Harness Review

Verdict: Looks good

This is a straightforward, mechanical refactor that reclassifies a set of "resource does not exist" conditions from InputValidationError to the more specific ResourceNotFoundError, with tightened messages.

Confidence-boosters I checked:

• ResourceNotFoundError extends InputValidationError (src/errors/errors.tsx:87), so any existing instanceof InputValidationError checks (e.g. resolveAgentToNameAndId in src/core/eval.tsx:1963) remain valid.
• The container test at src/core/dev/container.test.ts was correctly tightened to toBeInstanceOf(ResourceNotFoundError) for both changed cases.
• Grepped for the old message fragments ("does not exist in credentials[]", "container build context directory not found", "has no version", "the service returned no harness", etc.) — no other tests, snapshots, or callers still depend on them. The one remaining occurrence in src/projectSchemas/project.ts:292 is an unrelated Zod refinement message.
• No telemetry instrumentation is warranted; this is a reclassification of existing errors, not a new feature or code path.

Nothing to change. Ship it.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 96.87500% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 97.06%. Comparing base (4a23516) to head (945b3a5).

Files with missing lines	Patch %	Lines
src/handlers/project/export/harness.ts	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##           refactor    #2286   +/-   ##
=========================================
  Coverage     97.06%   97.06%           
=========================================
  Files           569      569           
  Lines         39322    39322           
=========================================
  Hits          38167    38167           
  Misses         1155     1155           

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[notgitika]

makes me think if we should invest in something that would help us enforce this.

also, I'm seeing that class ResourceNotFoundError extends InputValidationError I'm not sure I understand this. Can we make the heirarchy better like so:

class UserError extends AgentCoreCLIError
class InputValidationError extends UserError
class ResourceNotFoundError extends UserError

[Hweinstock]

Yeah fully agree that is confusing. I think we can rework the structure of the errors to be more normalized.