chore(omo): vendor impeccable skill 4.6.0

Re-copy .opencode/skills/impeccable from upstream tag skill-v4.6.0
(8a0e198, engine 0.1.15), keep LICENSE, and re-apply the OmO path
rewrite and the critique routing line.

The documented rewrite missed the base-directory fallback in SKILL.md,
which ends at scripts rather than scripts/impeccable, so the upgrade
command now rewrites the scripts directory prefix. The skills README
also notes that the engine binary is downloaded by scripts/VERSION
rather than vendored.

.config/omo/skills/impeccable/SKILL.md

@@ -1,7 +1,7 @@
 ---
 name: impeccable
 description: Use when the user wants to design, redesign, shape, critique, audit, polish, clarify, distill, harden, optimize, adapt, animate, colorize, extract, or otherwise improve a frontend interface. Covers websites, landing pages, dashboards, product UI, app shells, components, forms, settings, onboarding, and empty states. Handles UX review, visual hierarchy, information architecture, cognitive load, accessibility, performance, responsive behavior, theming, anti-patterns, typography, fonts, spacing, layout, alignment, color, motion, micro-interactions, UX copy, error states, edge cases, i18n, and reusable design systems or tokens. Also use for bland designs that need to become bolder or more delightful, loud designs that should become quieter, live browser iteration on UI elements, or ambitious visual effects that should feel technically extraordinary. Not for backend-only or non-UI tasks.
-version: 4.3.1
+version: 4.6.0
 user-invocable: true
 argument-hint: "[shape · audit|critique · animate|bolder|colorize|delight|layout|overdrive|quieter|typeset · adapt|clarify|distill · harden|onboard|optimize|polish · init|document|extract|live|generate] [target]"
 license: Apache 2.0
@@ -29,6 +29,7 @@ Core principles:
 
 - **The brief wins.** Honor pinned aesthetics, eras, materials, fonts, and palettes even when they conflict with a saturated-pattern warning. Redirecting a clear brief toward your taste is failure.
 - **Refinement preserves; redesign replaces.** Refinement keeps the incumbent identity, behavior, copy, and everything outside scope. Ask before replacing factual copy or adding claims. Redesign keeps product truth, content, function, native affordances, and constraints, but treats the old look as evidence and anti-reference; choose a replacement world in new-work and replace DESIGN.md. Never split the difference into polish on the discarded look.
+- **Loaded symbols stay out of the decoration.** A subject's world does not license emblems tied to militarism, supremacy, or hate movements as motifs, badges, or ornament, such as the Rising Sun flag's rays, the Confederate battle flag, or Nazi-era insignia and their stylised variants; reach for that world's neutral forms instead. Content that documents such a symbol as fact stays as it is.
 - **Visual authority is evidence, not a filename.** Missing DESIGN.md alone does not make a project greenfield; new-work decides whether to preserve, expand, or replace the incumbent world.
 
 ## Modes