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  bypass the forced-strong outdated-ComfyUI hardening on loopback,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

js/common.js

@@ -223,16 +223,19 @@ function isValidURL(url) {
 }
 
 export async function install_pip(packages) {
-	if(packages.includes('&'))
+	if(packages.includes('&')) {
 		app.ui.dialog.show(`Invalid PIP package enumeration: '${packages}'`);
+		return;
+	}
 
 	const res = await api.fetchApi("/customnode/install/pip", {
 		method: "POST",
-		body: packages,
+		headers: { 'Content-Type': 'application/json' },
+		body: JSON.stringify({ packages: packages }),
 	});
 
 	if(res.status == 403) {
-		await handle403Response(res);
+		await handle403Response(res, "To use this feature, set 'allow_pip_install = true' in config.ini ([default] section), then restart ComfyUI (the config is read once at startup). This setting is independent of security_level.");
 		return;
 	}
 
@@ -263,11 +266,12 @@ export async function install_via_git_url(url, manager_dialog) {
 
 	const res = await api.fetchApi("/customnode/install/git_url", {
 		method: "POST",
-		body: url,
+		headers: { 'Content-Type': 'application/json' },
+		body: JSON.stringify({ url: url }),
 	});
 
 	if(res.status == 403) {
-		await handle403Response(res);
+		await handle403Response(res, "To use this feature, set 'allow_git_url_install = true' in config.ini ([default] section), then restart ComfyUI (the config is read once at startup). This setting is independent of security_level.");
 		return;
 	}