feat(tools): converge two-tier Quick/Pro selector onto .no fork

Port the dobetterlegal-tools two-tier quality stack to dobetternorge.no:
QUALITY_TIERS registry + resolveTier (ToolModels), dbnToolsResolveToolRun
(bootstrap), tier read+charge in the 6 analytical endpoints, Quick/Pro
UI + payload.tier on the 6 tool pages/JS, and the bounded
corpusContextForSummarize RAG fix (per-passage trim + total budget +
reranker_enabled). Back-compat: requests without `tier` keep legacy
engine behavior.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

assets/js/korrespond.js

@@ -280,7 +280,7 @@
       clarifications: pendingClarifications,
       force_draft:    !!forceDraft,
       use_my_case:    (typeof window.dbnGetUseMyCase === 'function') ? window.dbnGetUseMyCase() : false,
-      engine:         (document.querySelector('[name="korrEngine"]:checked')?.value ?? 'azure_mini'),
+      tier:           (document.querySelector('[name="korrTier"]:checked')?.value ?? 'quick'),
       length:         (document.querySelector('[name="korrLength"]:checked')?.value ?? 'standard'),
     };
     if (korrDocIds.length) payload.doc_ids = korrDocIds;