feat(config)!: one ordering for configuration sources, and a bootstrap deny rule

$DSH_HOME/.env had just become an ordinary environment layer, which left the
harness resolving user-facing values from a flattened process.env that could
no longer say where a value came from. A key stored through the web page
stayed shadowed by an older key in the user's own .env. An endpoint could be
redirected by the project: the invoking directory's .env is materialized like
every other layer, and a base URL decides where a resolved API key is sent, so
a DEEPSEEK_BASE_URL written into a model-editable workspace would send the
user's credential — and the prompts carrying their code — to whatever host
that file named.

Give every user-facing value one ordering, with four kinds of source:

  explicit for this run     per-operation override, CLI argument
  > authored by deployment  --config / --config-replace
  > this launch's shell     inherited process environment
  > product-managed store   settings.yaml, .credentials.yaml
  > discovered file         $DSH_HOME/.env
  > defaults                schema default, shipped base, public default

The domains differ only in which tiers exist. The earlier split — credentials
ranking the environment over the managed file while settings ranked over the
environment — was inconsistent: the distinguishing fact is who authored the
source, not the domain.

packages/util/environment owns an immutable snapshot with per-layer
provenance. getFrom(name, sources) searches only the layers a caller names,
and omitting one is a refusal rather than a demotion: the adapters ask for
['process', 'user-env'], so no reordering can let a project file back into a
decision it was excluded from.

isBootstrapOnly rejects, before anything is materialized, any .env setting a
variable that governs how a process launches (PATH, SHELL, NODE_OPTIONS,
LD_PRELOAD), where code or model-visible instructions load from (the whole
DSH_* namespace, HOME, XDG_*), or how the network is reached (proxy and CA
variables). The namespace is denied wholesale so a switch added later cannot
become settable by being forgotten, and there is no opt-out.

verify-config-source-ownership keeps both rules: no unregistered process.env
read under packages/*/*/src (26 allowlisted with reasons), and no apiKey,
baseURL, or headers inlined from the environment in shipped Cordis config —
removing those inlines is what makes the deployment tier meaningful.

apps/cli/src/app-cli-entry.ts

@@ -14,6 +14,7 @@ import { createRequire } from 'node:module'
 import { networkInterfaces } from 'node:os'
 import { resolve } from 'node:path'
 import { Context } from 'cordis'
+import { DSH_ENVIRONMENT_KEY, type EnvironmentSnapshot } from '@deepseek-ai/dsh-environment'
 import type { PatchOptions } from '@cordisjs/plugin-include'
 import yaml from 'js-yaml'
 import { boot, installFailLoud, loadOverlayPatches } from '@deepseek-ai/dsh-app-boot'
@@ -102,6 +103,8 @@ const includeYamlSchema = yaml.JSON_SCHEMA.extend(jsExprType)
 
 /** Constructor facts for one dsh invocation over the shared composition (argv already parsed by the surface bin). */
 export interface AppCLIEntryOptions {
+  /** This run's frozen environment, provided to the tree before any config entry mounts. */
+  environment: EnvironmentSnapshot
   /** Absolute path of the shared base config the Loader includes. */
   configPath: string
   /**
@@ -255,6 +258,9 @@ export class AppCLIEntry {
         ...this.patches,
       ]
     this.ctx = await boot('dsh', resolve(this.bootConfigPath()), patches, async (ctx) => {
+      // Before any config-tree entry mounts, so a plugin that resolves a
+      // user-facing value at construction already sees this run's layers.
+      ctx.provide(DSH_ENVIRONMENT_KEY, this.options.environment)
       await this.options.prepare?.(ctx)
       if (this.options.dev) await ctx.loader.create({ name: '@deepseek-ai/dsh-client-hmr' })
     })