Expand plugin host surface (#5205)

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies
> - The plugin system is the extension boundary for optional product
capabilities
> - Rich plugins need more than a worker entrypoint: they need scoped
database storage, local project folders, managed agents/routines, host
navigation, and reusable UI components
> - The LLM Wiki work exposed those missing host surfaces while keeping
plugin code outside the core control plane
> - This pull request expands the core plugin host, SDK, server APIs,
and UI bridge so plugins can declare and use those surfaces
> - The benefit is that future plugins can integrate with Paperclip
through documented, validated contracts instead of bespoke server or UI
imports

## What Changed

- Added plugin-managed database namespaces and migration tracking,
including Drizzle schema/migration files and SQL validation for
namespace isolation.
- Added server support for plugin local folders, managed agents, managed
routines, scoped plugin APIs, and plugin operation visibility.
- Expanded shared plugin manifest/types/validators and SDK
host/testing/UI exports for richer plugin surfaces.
- Added reusable UI pieces for file trees, managed routines, resizable
sidebars, route sidebars, and plugin bridge initialization.
- Updated plugin docs and example plugins to use the expanded host and
SDK surface.

## Verification

- `pnpm install --frozen-lockfile`
- `pnpm run preflight:workspace-links && pnpm exec vitest run
packages/shared/src/validators/plugin.test.ts
server/src/__tests__/plugin-database.test.ts
server/src/__tests__/plugin-local-folders.test.ts
server/src/__tests__/plugin-managed-agents.test.ts
server/src/__tests__/plugin-managed-routines.test.ts
server/src/__tests__/plugin-orchestration-apis.test.ts
ui/src/api/plugins.test.ts ui/src/components/FileTree.test.tsx
ui/src/components/ResizableSidebarPane.test.tsx
ui/src/pages/PluginPage.test.tsx ui/src/plugins/bridge.test.ts` passed:
11 files, 67 tests.
- Confirmed this PR changes 89 files and does not include
`pnpm-lock.yaml` or `.github/workflows/*`.

## Risks

- Medium: this expands plugin host contracts across db/shared/server/ui
and includes a new core migration (`0076_useful_elektra.sql`).
- The plugin database namespace validator is intentionally restrictive;
plugin authors may need follow-up affordances for SQL patterns that
remain blocked.
- Merge this before the LLM Wiki plugin PR so the plugin can resolve the
new SDK and host APIs.

> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.

## Model Used

- OpenAI Codex, GPT-5 coding agent, tool-enabled shell/git/GitHub
workflow. Context window size was not exposed by the runtime.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] If this change affects the UI, I have included before/after
screenshots
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>

ui/src/lib/queryKeys.ts

@@ -41,6 +41,8 @@ export const queryKeys = {
     labels: (companyId: string) => ["issues", companyId, "labels"] as const,
     listByProject: (companyId: string, projectId: string) =>
       ["issues", companyId, "project", projectId] as const,
+    listPluginOperationsByProject: (companyId: string, projectId: string, originKindPrefix: string) =>
+      ["issues", companyId, "project", projectId, "plugin-operations", originKindPrefix] as const,
     listByParent: (companyId: string, parentId: string) =>
       ["issues", companyId, "parent", parentId] as const,
     listByDescendantRoot: (companyId: string, rootIssueId: string) =>
@@ -171,6 +173,8 @@ export const queryKeys = {
     health: (pluginId: string) => ["plugins", pluginId, "health"] as const,
     uiContributions: ["plugins", "ui-contributions"] as const,
     config: (pluginId: string) => ["plugins", pluginId, "config"] as const,
+    localFolders: (pluginId: string, companyId: string) =>
+      ["plugins", pluginId, "companies", companyId, "local-folders"] as const,
     dashboard: (pluginId: string) => ["plugins", pluginId, "dashboard"] as const,
     logs: (pluginId: string) => ["plugins", pluginId, "logs"] as const,
   },

ui/src/lib/status-colors.ts

@@ -57,7 +57,10 @@ export const statusBadge: Record<string, string> = {
   failed: "bg-red-100 text-red-700 dark:bg-red-900/50 dark:text-red-300",
   timed_out: "bg-orange-100 text-orange-700 dark:bg-orange-900/50 dark:text-orange-300",
   succeeded: "bg-green-100 text-green-700 dark:bg-green-900/50 dark:text-green-300",
+  ok: "bg-green-100 text-green-700 dark:bg-green-900/50 dark:text-green-300",
+  warning: "bg-amber-100 text-amber-700 dark:bg-amber-900/50 dark:text-amber-300",
   error: "bg-red-100 text-red-700 dark:bg-red-900/50 dark:text-red-300",
+  info: "bg-sky-100 text-sky-700 dark:bg-sky-900/50 dark:text-sky-300",
   terminated: "bg-red-100 text-red-700 dark:bg-red-900/50 dark:text-red-300",
   pending: "bg-yellow-100 text-yellow-700 dark:bg-yellow-900/50 dark:text-yellow-300",