TKE-47: fix posts index routes

[wenjiehs]

Health Check Report

Source issue: TKE-47

Scope:

• Scheduled light health check only.
• Checked Astro build, cookbook Python syntax, git whitespace, existing Node tests, navigation explicit hrefs, and local link/image existence.
• Did not run Full Compile Sweep or real Tencent Cloud/TKE operations.

Deterministic fix:

• Updated src/content/docs/posts/index.md to use generated internal routes for the two post links instead of .md source paths.

Verification:

• npm run build passed.
• python3 -m py_compile cookbook/common/auth.py cookbook/common/logger.py cookbook/cluster/create_cluster.py cookbook/cluster/delete_cluster.py cookbook/cluster/describe_clusters.py cookbook/supernode/deploy_gpu_pod.py cookbook/workload/deploy_nginx.py passed.
• node --test test/navigation.test.mjs test/cookbooks.test.mjs test/create-cluster-autoupgrade.test.mjs passed, 10 tests.
• git diff --check passed.
• Local route/link/image scanner checked 162 Markdown files and 187 generated routes; missing link/image errors: 0 after the fix.

Skipped:

• Full dry-run compile across all docs.
• Live verification / real cloud resource operations.
• Mass-editing missing code fence languages; scanner found 925 unlabeled fences, which is broad documentation debt and outside this low-risk health-check fix.

Routing findings from health check:

• In-review issues without PR metadata: TKE-41, TKE-40.
• Stale draft PRs over 72h: TKE-45/PR TKE-45: add TKE node maintenance doc #50, TKE-44/PR TKE-44: update navigation test expectation #55, TKE-43/PR TKE-43: fix navigation test expectation #54, TKE-42/PR TKE-42: fix navigation test expectation #53.
• In-review issue with merged PR still open in workflow: TKE-38/PR TKE-38: make node-pool describe examples copyable #51.
• Done issues retaining live-verify-failed: TKE-9, TKE-7, TKE-6.

[wenjiehs]

Approved.

Scope matches TKE-47: only src/content/docs/posts/index.md changes, replacing .md source-path links with generated route links. Health Check Report is present with Static Compile and dry-run/link-scan evidence: npm run build, targeted cookbook py_compile, node tests, git diff --check, and route/link/image scanner. No Tencent Cloud/TKE live operation is involved.

CI note: GitHub build passed. preview failed and PR deploy skipped are non-content PR-environment failures for this review and do not block approval.

Formal GitHub approval could not be submitted because the available GitHub identity is the PR author.