feat(identity): real author photo across the site + About page rewrite

The photo is the identity evidence the external review flagged as the biggest
gap. One source image (Pictures/Professional Portrait with Blue Gradient
Background.png, 1254x1254), two sizes, WebP first with a JPEG fallback —
continuous tone is the case where WebP/JPEG beat PNG:

  640x640  42 KB JPG / 26 KB WebP   About page (190 CSS px)
  128x128   3 KB JPG /  2 KB WebP   author card + home hero avatar

It now appears in the About hero, the author card at the end of every post, the
home hero (both languages), and JSON-LD Person.image — the node search engines
read to associate the name with a face.

About went from 1,024 characters to five sections: identity with photo, "By the
numbers" (162 containers / 3 hosts / 71 essays / 0 hosting companies between me
and the servers), the real tech stack in four columns, the Hoelee Enterprise
block (website design and development is the main business, email hosting
secondary), and a contact split between hiring and business.

Also: the headshot's dark-blue background sits close to the page background, so
the photo, hero avatar and card avatar get a faint brand ring plus shadow.

Pictures/ keeps the converted JPG master next to the untouched PNG.

src/layouts/BaseLayout.astro

@@ -130,6 +130,7 @@ const nav = isZh
       alternateName: SITE.handle,
       url: SITE.url,
       email: SITE.email,
+      image: new URL(SITE.photo.large, SITE.url).href,
       sameAs: [SITE.linkedin, SITE.github, SITE.gitea, SITE.website].filter(Boolean),
       jobTitle: 'Full-stack Developer & DevOps Engineer',
       // The consultancy that does the client work — ties the blog's author node to