style(web): fix prettier config, format entire web/ tree

.prettierrc.json was missing "semi": false, so prettier wanted to add
semicolons to a codebase written without them (763 semicolon-free
statements vs. 150 with, in hand-written .ts; zero hand-written .svelte
files use them at all). That's why prettier --check failed on 249 files
— not because the code was unformatted, but because the config didn't
match the actual house style. Added "semi": false; left printWidth/etc
as configured (printWidth barely moves the failure count: 218/213/212
files at 100/120/140).

Ran `prettier --write .` with the corrected config. Verified
semantics-preserving before and after:
- eslint: 142 problems both before and after, byte-identical
- build passes, 38/38 tests pass
- token-stream diff (whitespace/semicolons/quotes normalized) on all
  218 changed files: only 52 had any remaining token change, all either
  trailing-comma removal (matching trailingComma: "none") or import/
  ternary reflow — no semantic changes
- live smoke test: Knowledge, Tasks, Fleet map, and a chat window
  (AgentTrace, markdown, Scope graph, activity rail) all render
  correctly, no console errors

Most of the diff is shadcn/ui vendor files (lib/components/ui/) moving
from the CLI's own style (double quotes, tabs, semicolons) to house
style; re-running `shadcn-svelte add` on a component will need a
follow-up format pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/src/lib/components/Spinner.svelte

@@ -12,7 +12,11 @@
 <svg viewBox="0 0 24 24" class={className} fill="none" aria-hidden="true">
   {#each Array.from({ length: TICKS }) as _, i (i)}
     <rect
-      x="11" y="1.5" width="2" height="6" rx="1"
+      x="11"
+      y="1.5"
+      width="2"
+      height="6"
+      rx="1"
       fill="currentColor"
       opacity="0.15"
       transform="rotate({i * (360 / TICKS)} 12 12)"