fix: folder palette single-source, spec sync, new-chat row labels

[krishdhasmana]

Problem

Follow-up to the sidebar folder redesign (#1211). Three loose ends from that change:

• The folder color palette existed in three places with only comments holding them together: the backend allowlist (12 hexes), the frontend catalog (12), and a private 8-hex list on the Artifacts page. Nothing enforced agreement, and the backend's KEEP-IN-SYNC comment pointed at a file that no longer exists. Drift would mean the modal offers a swatch the backend rejects with a 400.
• The folder API spec (docs/system-specs/modules/learn-cron-dashboard.md) still documented the removed icon contract: background LLM emoji-icon generation on create and icon on PATCH. An agent reading the spec would code against a removed API.
• The empty-folder "new chat" rows showed the generic "New chat in folder" as their visible label while the stronger interpolated "New chat in {{name}}" string, already localized in every catalog, was only used for aria.

Why it matters

Palette drift is a silent runtime failure (UI offers, backend 400s). The stale spec violates the repo's same-commit doc rule and misleads the next contributor. The generic row label wastes an already-localized, more informative string.

Fix (symptoms -> root cause -> change)

Palette single-sourcing: ArtifactsPage.tsx drops its private FOLDER_COLORS (an exact subset of the 12) and imports the shared FOLDER_COLOR_PALETTE from folderColorCatalog.tsx, so artifact folders gain the four missing hues (orange, lime, teal, indigo) and the swatch aria labels become the localized color names instead of a hardcoded Color #hex literal. Existing artifact-folder colors are unaffected (the artifacts backend shape-validates #rrggbb only, and the old 8 remain in the 12). The backend allowlist stays a separate Python constant by necessity, but test_folder_color_palette_matches_frontend_catalog now parses the hexes out of the tsx and asserts set-equality, so drift fails CI. The allowlist comment points at the real catalog file and names the test.

Spec sync: the Chat Folders section now documents the shipped contract: color on create and PATCH (allowlisted, 400 with machine-readable code: "color_invalid", empty or null clears), no icon field on the folder model, stale stored icon values ignored, and no LLM generation in the chat-folder lifecycle (the artifact-library emoji generator is a separate, unaffected system).

Row labels: both empty-folder new-chat rows (list and board views) render New chat in {{name}} as their visible label, and the folder-header new-chat buttons use the same interpolated string for tooltip and aria, replacing one hardcoded English template literal on the board-view button.

Tests

• test_folder_color_palette_matches_frontend_catalog (backend): pins the backend allowlist to the frontend catalog; either side drifting breaks CI.
• Existing suites cover the touched surfaces: 69 targeted backend folder/color tests, 501 frontend tests across sidebar/folder/artifact suites, strict i18n:check, docs-lint.

Manual verification

N/A: unit and gate coverage sufficient. The changes are a constant import swap, prose, and i18n key substitutions on existing rows; no new visual states beyond four additional swatches rendering identically to the existing eight.

Screenshots

Before/after for both user-visible surfaces (rendered from the shipped components in a capture harness):

Artifacts folder color swatches: 8 hues with hex-only labels, now the shared 12-hue catalog with localized color-name tooltips.

Empty-folder new-chat row: generic label, now the folder's name interpolated.

The spec and pinning-test changes have no visual surface.

[github-actions]

Design Review (Fable 5) — ✅ PASS

Advisory design-level review of e346668d70876ad486f63e01619f431df75b8892 — updated in place on each push; does not block merge.

Design-Verdict: PASS

Genuine drift risk closed at its root (one catalog, one fail-closed CI pin); every hunk is backed and proportionate.

[DESIGN-REVIEWED] e346668

[github-actions]

UX Review (Fable 5) — ✅ PASS

Advisory UX-level review of e346668d70876ad486f63e01619f431df75b8892 — updated in place on each push; does not block merge.

UX-Verdict: PASS

Strictly clarifying change: swatches gain real color names, rows name their folder — screenshots confirm the rendered result matches the claims.

Suggestions

• In ChatSidebar.tsx, the empty-folder row's <span>{i18nT('pages.chatSidebar.new_chat_in_name', …)}</span> has no truncate while every sibling folder-name span does — a long folder name now wraps the row to multiple lines; add truncate min-w-0 (the title already carries the full string).

[UX-REVIEWED] e346668

[github-actions]

Opus 5 Review — ✅ no blocking findings

Reviewed e346668d70876ad486f63e01619f431df75b8892 — this comment is updated in place on each push.

Review details

No findings.

[OPUS-REVIEWED] e346668

Verdict parsed from the review's SHA-scoped output markers for commit e346668d70876ad486f63e01619f431df75b8892.

False positive or not applicable? A repository writer can comment:
/ai-review override fable e346668d70876ad486f63e01619f431df75b8892: <one-sentence reason>

[github-actions]

GPT 5.6 Review — ✅ no blocking findings

GPT 5.6 completed its review of e346668d70876ad486f63e01619f431df75b8892 and found no blocking issues.

This comment is updated in place on each push.

Review details

No findings.
[GPT-REVIEWED] e346668

False positive or not applicable? A repository writer can comment:
/ai-review override gpt e346668d70876ad486f63e01619f431df75b8892: <one-sentence reason>

[bolichen97]

Open PR relationship audit

This is a consolidated, point-in-time code-level audit note. It compares complete merge-base diffs and current/merged code; it does not treat a shared topic as duplication or partial coverage as completion.

Relationship findings

• PR #7353 is OVERLAPPING relative to this PR. The goals differ or the implementations can complement each other; this is not a duplicate claim. Recommended action for PR #7353: MERGE_DISCUSSION. Reinforces the PR #1211 finding: the no-icon position is documented as an invariant by a second merged change, so accepting PR #7353 is an explicit spec reversal that the maintainer should sign off on rather than a documentation catch-up. Files: docs/system-specs/modules/learn-cron-dashboard.md.

No PR, Issue, label, branch, or review state was changed by the relationship-note portion of this audit.