feat(studio): add Tessera fair-value preset and staleness chip

[92Infinitus92]

Pairs with LimeChain/surfpool#11 (the create_tessera_fair_value_scenario tool and the tessera templates) — merge after it, the preset needs that backend.

Stacked on #9 — reuses its string-values scenarios API, the constant-catalog fetch and the MCP creator seam.

• "PMM fair value" preset: market picker fed by the 26-pair catalog (free-text address fallback when the catalog fails to load), price input, and creation through the create_tessera_fair_value_scenario MCP tool — no client-side math, the backend derives both ratio fields.
• "Tessera Stale Quote" AI chip, goal-level like every other protocol's chip; the procedure lives in the backend template's llm_context.
• Three file-internal phoenix helpers are generalized instead of duplicated (scenarioTemplate, createScenarioWithMcpTool, ScenarioCreationResult) — expect a small, mechanical conflict on those lines when this merges alongside the phoenix branch.
• 317 tests green, tsc clean.

Greptile Summary

The PR adds a Tessera fair-value preset, live market discovery with a free-text fallback, Tessera scenario-editor support, and stale-quote/depth-stress AI prompts.

• Creates fair-value scenarios through the paired Tessera MCP tool.
• Adds Tessera protocol metadata, iconography, and raw-layout field handling.
• Preserves wide integer values and original account metadata while editing scenarios.

Confidence Score: 5/5

The PR appears safe to merge with its explicitly paired Surfpool backend change.

No blocking failure remains; the only prior finding was invalidated after the paired backend PR was verified to register the required Tessera tool and template.

Important Files Changed

Filename	Overview
apps/studio/src/lib/scenarios-api.ts	Adds Tessera market discovery and fair-value scenario creation through the generalized MCP helper.
apps/studio/src/components/svm/pmm-fair-value-dialog.tsx	Implements catalog-backed market selection, fallback address entry, price validation, and scenario creation feedback.
apps/studio/src/components/svm/scenario-editor.tsx	Enables Tessera templates while preserving raw-layout wide integers and loaded override metadata during edits.
apps/studio/src/components/svm/scenarios-bento.types.ts	Adds Tessera stale-quote and depth-stress example prompts.
apps/studio/src/lib/scenario-fields.ts	Derives editable fields and integer encodings for IDL-less raw-layout templates.

Sequence Diagram

sequenceDiagram
  actor User
  participant UI as Studio UI
  participant MCP as Surfpool MCP
  participant Store as Scenario Store
  UI->>MCP: list_tessera_markets
  MCP-->>UI: "markets[{label,address}]"
  User->>UI: Select market and enter price
  UI->>MCP: "create_tessera_fair_value_scenario({market?, price})"
  MCP->>Store: Validate market and create overrides
  Store-->>MCP: Scenario ID
  MCP-->>UI: "{url: /scenarios?id=...&tab=editor}"
  UI-->>User: Open scenario editor

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_{Reviews (9): Last reviewed commit: "fix(studio): reconcile market selection ..." | Re-trigger Greptile}

[github-actions]

• pmm-fair-value-dialog.tsx:80 — The empty initial catalog is treated as a failed catalog. While loading, users see free-text input and can submit any market before the catalog resolves, bypassing catalog-only validation. Track an explicit loading state and enable fallback only after loading finishes unsuccessfully.

[github-actions]

• scenarios-api.ts:171 — Blocking: The preset calls create_tessera_fair_value_scenario and expects tessera-fair-value, but the coupled Surfpool backend exposes neither contract. Catalog loading falls back to free text, then every creation attempt fails. Land/version the backend support before enabling this UI, or feature-detect the tool/template and hide the preset.

[github-actions]

• Medium — pmm-fair-value-dialog.tsx:46: canCreate remains true while marketOptions === null. After reopening, a previously selected market persists and can be submitted while the UI displays “Loading markets…”, bypassing catalog validation. Require catalog loading to finish before enabling creation, or reset market when opening.

[github-actions]

• scenario-editor.tsx:394: Raw Tessera u64/u128 fields are classified as numeric, then converted with Number(...) when edited. Atomic ratio values can exceed Number.MAX_SAFE_INTEGER, causing precision loss before saving. Preserve these values as decimal strings, consistent with the string-values API.

[github-actions]

• Minor: reconcile the selected market when refreshing the catalog (pmm-fair-value-dialog.tsx:110). current || options[0]?.value retains a previously entered address even if it is absent from the refreshed catalog. After fallback entry or a catalog change, reopening can show an empty selection and disable creation. Keep current only if it exists in the new options; otherwise select the first market.

No other concrete issues found in the PR changes. Tests could not run because pnpm is unavailable.

[github-actions]

• [P2] Preserve the existing account only when the template is unchanged — scenario-editor.tsx:749. While editing an override, users can select another action from the sidebar. Updating now saves the new template with the old action’s account—for example, switching Phoenix collateral stress to a market action retains the trader account. This can cause validation failures or target the wrong account. Use the new template’s address when actionId changes, and add a regression test for switching templates.

Tests weren’t run; dependencies are not installed.