feat: extend extensions — install from Hub/zip, schema inspection, Ac…

[MaciejGrynda]

feat: extend extensions — install from Hub/zip, schema inspection, ActiveGate groups

• add dtctl create extension with --hub-extension and -f (zip upload) flags
• add --monitoring-configuration-schema, --no-fluff, --active-gate-groups to describe extension
• add extensions:definitions:write scope to all write-capable safety levels
• add unit, integration, and golden tests for all new functionality

Description

Related Issues

Closes #143

Testing

• [ X ] Tests pass (make test)
• [ X ] Linting passes (make lint)
• Manual tests

[discostu105]

Code review

Found 3 issues:

1. printer.Print(groups) serializes *ActiveGateGroupList as {"items":[...]} in JSON/YAML/CSV output instead of the bare array [...]. Other list commands (e.g. get_hub_extensions.go) use printer.PrintList(list.Items). The fix is return printer.PrintList(groups.Items).

dtctl/cmd/describe_extensions.go

Lines 165 to 168 in 0c7029f

	enrichAgent(printer, "describe", "extension")
	return printer.Print(groups)
	}

2. docs/dev/IMPLEMENTATION_STATUS.md still shows create as - for extension, but this PR implements dtctl create extension. This was also a blocker in the review of the predecessor PR feat: Extend coverage of Extensions 2.0 functionality in dtctl #150.

dtctl/docs/dev/IMPLEMENTATION_STATUS.md

Lines 76 to 79 in 0c7029f

	| lookup | ✅ | ✅ | ✅ | ✅ | - | ✅ |
	| extension | ✅ | ✅ | - | - | - | - |
	| extension-config | ✅ | ✅ | - | - | - | ✅ |
	| intent | ✅ | ✅ | - | - | - | - |

3. Both runUploadExtension and runInstallHubExtension embed name and version into the PrintSuccess string, rather than following the pattern used by other create commands (e.g. create_workflows.go L87-90) of calling PrintSuccess for the headline and then PrintInfo lines for ID/URL details. This was flagged as a blocker in PR feat: Extend coverage of Extensions 2.0 functionality in dtctl #150 and remains unaddressed.

dtctl/cmd/create_extensions.go

Lines 86 to 91 in 0c7029f

	}
	output.PrintSuccess("Extension %q version %s uploaded successfully", result.ExtensionName, result.Version)
	return nil
	}

dtctl/cmd/create_extensions.go

Lines 111 to 115 in 0c7029f

	}
	output.PrintSuccess("Hub extension %q version %s installed successfully", result.ExtensionName, result.Version)
	return nil
	}

[discostu105]

Reviewed and tested locally — all tests pass, build and vet clean. Code looks solid: good flag validation, thorough error handling, comprehensive test coverage including golden tests. A few minor observations (non-blocking): StripSchemaFluff mutates the input map in-place, no file size guard on zip upload, and the ActiveGateEntry.Errors unmarshal error is silently swallowed in the table formatter. None of these are blockers. LGTM.