feat(security): dedicated install flags decoupled from security_level (#2991)

* feat(security): add dedicated install flags decoupled from security_level

Gate 'install via git URL' and 'install via pip' with dedicated opt-in
boolean flags (allow_git_url_install / allow_pip_install) in config.ini
[default], fully replacing the security_level term on those surfaces
(REPLACE, not AND — a strict level no longer denies when the flag is on;
a weak level no longer allows when the flag is off).

- glob/manager_server.py: pure predicate is_dedicated_install_allowed
  (flag AND loopback, request-time args.listen); REPLACE gates at
  /customnode/install/git_url and /customnode/install/pip; batch
  unknown-URL arm routes through the same full predicate at the risky
  position (loopback term is load-bearing — the middle entry gate has
  no network-position term; the entry gate itself stays in force);
  unknown-pip in batch stays unconditionally blocked; new
  SECURITY_MESSAGE_FLAG_* denial constants name the responsible flag;
  security_403_response gains flag_token (comfyui_outdated keeps precedence)
- glob/manager_core.py: register both keys (read via get_bool default-false,
  write list, exception fallback); "true"-only truthy; restart-only activation
- js/common.js: 403 dialog copy names the responsible flag at the two
  install call sites
- README.md: security-policy docs for both flags (per-surface scope incl.
  the batch entry-gate qualifier, REPLACE decoupling, loopback bound,
  opt-in config snippet, default-deny + migration note); stale tier lists
  corrected against the actual gates
- CHANGELOG.md: opt-in migration note + accepted residual risk (flags
  bypass the forced-strong outdated-ComfyUI hardening on loopback,
  opt-in only), decoupling claim qualified for the batch entry gate

Tests: unit suite (predicate truth table, REPLACE litmus both directions,
AST binding-proofs against live handlers, subprocess-isolated config
contract) plus a real-server E2E suite that mounts the Manager-under-test
via git worktree (exact-SHA pin, detached) against a real ComfyUI and
exercises both flag surfaces and both arms — deny arms (403 + flag-naming
body/log + no install artifact), git-URL allow arm (real clone), pip allow
arm as a two-phase reservation oracle — with zero-residual self-clean.
Module skips without E2E_COMFYUI_ROOT; unit suite unaffected.

The manager-v4 branch ships the identical policy (shared invariants +
config contract); this tree uses the degraded predicate 'flag AND
loopback' (no personal_cloud-equivalent mode here).

* bump version to v3.41

README.md

@@ -384,19 +384,79 @@ When you run the `scan.sh` script:
       * all feature is available
     
   * `high` level risky features
-    * `Install via git url`, `pip install`
-    * Installation of custom nodes registered not in the `default channel`.
-    * Fix custom nodes
+    * Downloading models that are not in `.safetensors` format and not
+      registered in the `default channel` model list
+    * NOTE: `Install via git url`, `pip install`, and installation of custom nodes
+      not registered in the `default channel` are **no longer governed by
+      `security_level`** — they are governed by the dedicated install flags
+      described below.
   
   * `middle` level risky features
     * Uninstall/Update
     * Installation of custom nodes registered in the `default channel`.
+    * Fix custom nodes
     * Restore/Remove Snapshot
     * Restart
   
   * `low` level risky features
     * Update ComfyUI
 
+### Dedicated install flags: `allow_git_url_install` / `allow_pip_install`
+
+The two arbitrary-install surfaces are governed by dedicated boolean keys in
+`config.ini` (`[default]` section), fully **decoupled** from `security_level`:
+
+  * `allow_git_url_install`
+    * governs `Install via Git URL` (`POST /customnode/install/git_url`) **and**
+      the unknown-git-URL arm of the batch install queue
+      (`POST /manager/queue/install`, including reinstall delegation) — i.e.
+      installing any custom node from a git URL that is not registered in the
+      `default channel` catalog
+    * on the **batch queue path**, the flag is **necessary but not
+      sufficient**: the queue's normal `security_level` entry gate (`middle`)
+      must ALSO pass — at `security_level = strong`, batch unknown-URL
+      installs stay denied even with the flag set to `true` (only the direct
+      `Install via Git URL` endpoint is fully independent of `security_level`)
+    * covers the **entire install transaction** it starts, including the
+      pack's transitive dependency pip installs
+  * `allow_pip_install`
+    * governs **only** the standalone `pip install` feature
+      (`POST /customnode/install/pip`)
+
+Key properties:
+
+  * **Decoupled from `security_level` (replace, not and)** — on the two
+    **direct endpoints** (`Install via Git URL` and `pip install`),
+    `security_level` no longer has any effect in either direction: a strict
+    level cannot deny them when the flag is `true`, and a weak level cannot
+    allow them when the flag is `false`. (The batch queue path keeps its
+    `security_level` entry gate in ADDITION to the flag — see the scope bullet
+    above.) Every other gated feature remains governed by `security_level` as
+    described above.
+  * **Loopback only** — the flags take effect **only** when the server listens
+    on a loopback address (e.g. `--listen 127.0.0.1`). On a non-loopback
+    listener these surfaces stay denied regardless of the flags; the flags
+    never widen the exposure of a public deployment.
+  * **Default deny / explicit opt-in** — both flags default to `false`. Only
+    the case-insensitive string `true` enables a flag; a missing or malformed
+    key reads as `false`.
+
+To opt in, edit `config.ini`:
+
+```ini
+[default]
+allow_git_url_install = true
+allow_pip_install = true
+```
+
+Changes take effect after a **restart** (no hot reload).
+
+> **Migration note**: there is no automatic migration from `security_level`.
+> If you previously relied on `security_level = weak` (or `normal-`) to use
+> install-via-git-URL / pip install, you must opt in explicitly with the flags
+> above. See `CHANGELOG.md` for details, including a behavior note for
+> outdated ComfyUI deployments.
+
 
 # Disclaimer