## Why

Local operators can configure `platform/.env`, but the platform process currently reads only inherited environment variables. This makes MySQL metadata storage look uninitialized even when the `.env` file contains the correct `PLATFORM_STORAGE_BACKEND=mysql` and `PLATFORM_MYSQL_DSN` settings.

The current personal configuration experience is embedded in the sidebar account popover, which is cramped for profile, theme, and background preferences. Operators need a normal first-party personal settings page that saves profile and theme changes through platform APIs so values are durable in the configured metadata store.

## What Changes

- Load platform environment variables from local `.env` files before building platform configuration, while preserving explicit process environment overrides.
- Keep MySQL metadata initialization database-backed and make configured storage selection testable so operators can verify the remote metadata store is actually used.
- Replace the sidebar profile popover with a dedicated personal settings page for profile, theme palette, background preset, uploaded background, and logout actions.
- Add the personal settings route to the shell for authenticated users and keep account edits wired to `/api/v1/users/current/profile` and `/api/v1/users/current/theme`.
- Preserve the magical-girl crystal-moonlight visual system by reusing shared shell/page surfaces and theme tokens rather than adding a one-off UI style.

## Capabilities

### New Capabilities

- `platform-env-bootstrap`: Platform startup loads local environment configuration and initializes the configured metadata backend predictably.
- `personal-settings-workspace`: Authenticated users manage their own profile and console theme preferences from a full settings page backed by platform APIs.

### Modified Capabilities

- None.

## Impact

- Affects `platform/config` and platform startup tests for `.env` loading and storage backend selection.
- Affects `platform_web` route definitions, page registry, shell account controls, session usage, API-bound personal settings UI, tests, and shared styling.
- Does not add billing, cloud host sales, external marketplace behavior, raw AI key exposure, or plugin direct access to platform/run internals.