Fix noImplicitAny and strict TypeScript indexing issues

[flicksolutions]

Summary

This PR addresses strict TypeScript failures on branch AI-Type-fixes by fixing noImplicitAny and dynamic indexing issues directly in code (without relaxing compiler settings).

What Was Done

• Added explicit parameter and return types in utility helpers.
• Reworked dynamic dictionary/JSON indexing with typed Record<...> maps and guarded access.
• Added stricter prop/snippet/event typings in Svelte components where implicit any was inferred.
• Narrowed route params and derived values before indexing nested data objects.
• Fixed server/page typing issues in edition/register/sequence/topic/network routes.

Key Areas Updated

• Helpers in src/lib/functions/ease_of_use/* (including slugify, updateSearchParams, normalizeChars, findKeyBySlug, filterAndSortData)
• CETEI behaviors typing in src/lib/CETEIcean/behaviors.ts
• Overview/Register UI components (OverviewContent, RegContent, Register)
• Route-level typing fixes for:
  • src/routes/edition/[docPickerId=docPickerId]/+page.svelte
  • src/routes/edition/[docId=docId]/+layout.server.ts
  • src/routes/edition/register/[regSlug=regSlug]/+page.server.ts
  • src/routes/sequences/[seqId=seqId]/+page.svelte
  • src/routes/networks/+page.svelte
  • src/routes/topics/[topic]/+page.svelte

Validation

• pnpm check now reports no TypeScript errors on this branch after the strict typing fixes.
• Existing non-type warnings (primarily accessibility and markup warnings) remain out of scope for this PR.

[flicksolutions]

This was all done by GPT-5.3-Codex please review with great care @vvvyyynet .