chore: bump Golang to 1.26

[mbevc1]

• Use latest Go for build and as a minimum version
• Trailing white spaces clean-up
• Dockerfiles updates

[mbevc1]

@dependabot unignore k8s.io/kubernetes minor version

[claude]

Claude finished @mbevc1's task in 1m 52s —— View job

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PR Review: Bump Golang to 1.26

• Run static analysis (build, vet, mod tidy)
• Review code changes
• Post review feedback

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Static Analysis

All checks pass:

• go build ./... — compiles cleanly
• go vet ./... — no issues
• go mod tidy — no diff (dependencies are clean)

Review

Overall: This PR looks good. It's a straightforward Go version bump with consistent Dockerfile updates and a helpful trailing-whitespace cleanup.

Version consistency

File	Value	Status
.go-version	1.26	✅
go.mod	go 1.26.3	✅
Dockerfile	GO_VERSION="1.26"	✅
Dockerfile	ALPINE_VERSION="3.23"	✅
Dockerfile.alpine	ALPINE_VERSION=3.23	✅
Dockerfile.alpine	KOSLI_VERSION=2.17.7	✅

No leftover references to Go 1.25 found in the codebase.

Note on my previous review comment: I flagged a potential go.mod downgrade from 1.26.3 to 1.26.2 — that was based on an intermediate commit state. The final state correctly has go 1.26.3 throughout. That comment can be disregarded.

Trailing whitespace cleanup (root.go, dev-guide.md, snyk.md)

Clean removal of trailing \x20\x20 from string literals and markdown. The changes in root.go are cosmetic-only — no semantic changes to command descriptions.

Minor observation: A few trailing spaces remain in cmd/kosli/testdata/output/docs/mintlify/snyk.md (lines 5, 14, 15) and artifact.md (line 17), but these are likely generated golden files whose content is driven by command output. Cleaning those would require fixing the source descriptions elsewhere — not in scope for this PR.

Docker changes

• Alpine 3.21 → 3.23 in Dockerfile (already 3.23 in Dockerfile.alpine on main — now consistent)
• Kosli CLI version 2.13.1 → 2.17.7 in Dockerfile.alpine — sensible bump

No concerns

• No logic changes — purely version bumps and whitespace
• No security implications
• No test changes needed (whitespace cleanup in golden file is consistent with the root.go changes)

👍 LGTM — clean version bump with good housekeeping.

[mbevc1]

This should unblock ignoring Kubernetes upgrades: #831