feat: encrypted secrets vault across CLI, desktop, dashboard, and backend

Local vault (apps/cli): clean-room PRMVLT01 format — Argon2id →
XChaCha20-Poly1305, AEAD-bound header, atomic writes. vault:* / secrets:*
/ inject (primora:// refs) / agent credential broker (dummy tokens in the
child, real secret on the wire) / TTL sessions / stack:* operator group.

Project vault (backend): core.project_secrets, AES-256-GCM via the
platform encryptor. Metadata-only list, audit-logged reveal, and
secret://NAME refs resolved at job delivery — refs stored, values never.

Surfaces: dashboard Vault page (+ local-vault card under the Tauri
shell), desktop vault window via IPC to the primora binary,
secrets:* --remote CLI mode, metadata/write-only MCP tools so agents
consume secrets via secret:// refs without holding plaintext.

Authored By: TDvorak <[email protected]>

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

README.md

@@ -91,9 +91,9 @@ and [QUICK_START.md](QUICK_START.md#configuration) for the important ones.
 
 ## Ecosystem
 
-- **[CLI](apps/cli)** - `primora` for orgs, projects, buckets, objects, keys, and audit from the terminal.
+- **[CLI](apps/cli)** - `primora` for orgs, projects, buckets, objects, keys, jobs, and audit — plus an encrypted local secrets vault (`vault:*`, `secrets:*`, `inject`), the shared project vault (`secrets:* --remote`, `secret://NAME` refs in job payloads), an agent credential broker (`agent`), and compose-stack operator commands (`stack:*`).
 - **[MCP server](apps/mcp)** - exposes `primora_*` tools to MCP clients.
-- **[Desktop](apps/desktop)** - Tauri 2 shell connecting to your deployment, with tray presence.
+- **[Desktop](apps/desktop)** - Tauri 2 shell connecting to your deployment, with tray presence and a local Secrets Vault window (drives the CLI's vault).
 - **PWA** - the dashboard is installable on mobile and desktop browsers.
 
 ## Documentation