@cah make the border thinner. Also do not touch anything inside the outer border

@robin updated the logo assets for review.

Changes made:

• reduced the contrast outline from the previous thick border to a 24 px outline on the 700 px PNGs
• regenerated from the original target-branch assets so existing non-transparent logo pixels are unchanged
• limited the new outline to the outer silhouette, leaving the interior artwork untouched

Verification:

• confirmed original logo pixels have 0 differences against the target-branch versions
• visually inspected the regenerated PNGs
• attempted mvn -pl server-core -am -DskipTests compile, but this workspace does not have mvn on PATH

@cah the dark version is completely messed up, please work from original version. This is the mess:

@robin regenerated the PNG outlines from the original base assets for review.

Changes made:

• rebuilt server-core/src/main/java/io/onedev/server/web/img/logo.png and server-core/src/main/java/io/onedev/server/web/img/logo-dark.png from the original PR base versions
• reduced the contrast outline to 12 px
• limited new pixels to the exterior perimeter of the outer logo artwork, leaving the original non-transparent pixels unchanged

Verification:

• confirmed both regenerated assets have 0 changed original non-transparent pixels, with only new outline pixels added
• visually inspected checkerboard previews for both assets
• attempted mvn -pl server-core -am -DskipTests compile, but this workspace does not have mvn on PATH