fix: rewrite meld v0.1.0 post for accuracy, add per-post git info

[avrabe]

  Rewrite the meld blog post addressing feedback:
  - Remove misleading P1/P2 framing — adapter bridges @0.2.0 to @0.2.6
  - Remove wasm-tools strip workflow — show actual meld output sizes
  - Reduce WAT dumps, lead with try-it-yourself workflow
  - Clarify 4-module structure as toolchain artifact, not CM requirement

  Add per-post git revision info to deploy pipeline:
  - inject-git-info.py injects last_commit and commit_count into frontmatter
  - deploy.yml runs script before zola build (with fetch-depth: 0)
  - blog-page.html displays commit hash linked to GitHub + revision count