Navigation and content-layout redesign

[GregorShear]

Summary

Redesigns the app shell around a collapsible left sidebar and a content-area header, and moves app icons from iconoir-react to lucide-react.

Changes

Navigation

• Collapsible left sidebar (full width ↔ icon rail). The user menu, help menu, Agent Skills entry, and the dark-mode toggle now live in the sidebar instead of the top bar.
• Top bar reduced to the logo (CompanyMark when collapsed), update alert, and docs toggle.
• ListItemLink takes route links (link) and action handlers (onClick) as separate props, with active-route highlighting via useMatch.

Layout / theme

• Grid-based Layout with a content header in PageContainer that shows the page title.
• Theme: rounded buttons/icon buttons, drawer and list overrides, lucide icon sizing.
• Icons migrated to lucide-react across the app. iconoir-react is kept as a dependency for the remaining usages.

Pages

• Per-page "New" create buttons restored on captures / collections / materializations.

Notes for reviewers

• Rebased onto main and squashed into a single commit. Reconciled with work merged since this branch diverged: the AgentSkills PR (Promote Agent Skills docs on the dashboard #1975 / Fixing zindex for LLM skills toast and hiding when docs are open #1985) and the i18n-deprecation refactor (Deprecate i18n props #2009).
• ListItemLink keeps the named-export + deprecated-wrapper pattern (the react-intl-removal scaffold), and the AgentSkills toast keeps the Fixing zindex for LLM skills toast and hiding when docs are open #1985 "hide when docs panel is open" behavior.
• The large file count is mostly the mechanical iconoir-react → lucide-react swap.

Testing

• npm run typecheck and npm run lint pass.
• Visual QA of the expanded/collapsed sidebar (icon alignment) is still pending.

[github-actions]

✅ Code Health

Removes $\textcolor{green}{2}$ dead-code issues, introduces none.

59 Dead files $\textcolor{green}{-1}$

File imported nowhere — delete (or import) it.

$\textcolor{green}{-}$ src/components/shared/RelativeAppBar.tsx
     src/hooks/useDelay.ts
     src/hooks/useDraft.ts
     src/hooks/useExpressWorkflowAuth.ts
     src/pages/NoGrants.tsx
     src/pages/OAuth.tsx
     src/services/encryption.ts
     src/types/global.ts
     src/types/vitest.ts
     src/components/graphics/PoweredByEstuaryWatermark.tsx
…and 50 more

82 Dead symbols

Symbol used nowhere — export hides it from the linter; delete it

     src/context/Theme.tsx : logoColors
     src/context/Theme.tsx : intensifiedOutlineThick
     src/context/Theme.tsx : tableAlternateRowsSx
     src/context/Theme.tsx : draggableChipIconSx
     src/context/Theme.tsx : hiddenButAccessibleInput
     src/context/Theme.tsx : primaryColoredBackground_hovered
     src/context/Theme.tsx : detailsPanelBgColor
     src/context/Theme.tsx : menuBackgroundColor
     src/context/Theme.tsx : flexGrowToSiblingsSx
     src/context/Theme.tsx : shardTableRow
…and 72 more

14 Dead enum members

An enum member referenced nowhere

     src/services/supabase.ts : CONNECTOR_TAGS
     src/services/supabase.ts : DRAFTS_EXT
     src/services/supabase.ts : TASKS_BY_DAY
     src/stores/names.ts : QUEUED_TASKS
     src/stores/Tables/hooks.ts : accessGrants
     src/stores/Tables/hooks.ts : accessLinks
     src/stores/Tables/hooks.ts : billing
     src/stores/Tables/hooks.ts : connectors
     src/stores/Tables/hooks.ts : entitySelector
     src/stores/Tables/hooks.ts : prefixes
…and 4 more

177 Unnecessary exports $\textcolor{green}{-1}$

Exported but only used within its own file — just drop export

$\textcolor{green}{-}$ src/components/navigation/ListItemLink.tsx : ListItemLink
     src/context/Theme.tsx : sample_blue
     src/context/Theme.tsx : successDark
     src/context/Theme.tsx : infoMain
     src/context/Theme.tsx : chipDraggableIndex
     src/context/Theme.tsx : headerLinkIndex
     src/context/Theme.tsx : alternativeDataGridHeader
     src/context/Theme.tsx : connectorCardLogoBackground
     src/context/Theme.tsx : wrappingTableCell
     src/utils/connector-utils.ts : DEKAF_IMAGE_PREFIX
…and 168 more

8 Unused dependencies

In package.json but never imported

     package.json : @mui/lab
     package.json : @testing-library/jest-dom
     package.json : @urql/exchange-retry
     package.json : logrocket-react
     package.json : stripe
     package.json : @types/logrocket-react
     package.json : @types/react-inspector
     package.json : sharp