feat(web_viewer): mask plugin password fields in settings (#273)

Add a password type to settings_schema so plugin secrets render as masked inputs and never reach the browser. Stored values stay in config.ini; an empty box on save leaves an existing secret unchanged.

modules/settings_schema.py

@@ -19,7 +19,7 @@ Schema field format (a list of these dicts on ``settings_schema``)::
     {
         "key": "poll_interval",        # config key within the section
         "label": "Poll interval",      # human label
-        "type": "int",                 # bool|int|float|str|enum|list
+        "type": "int",                 # bool|int|float|str|enum|list|password
         "options": [{"value": "...", "label": "..."}],  # required for enum
         "min": 1000, "max": None,      # numeric bounds (int/float)
         "default": 60000,
@@ -43,7 +43,7 @@ from typing import Any, Optional
 # so a plugin's on/off state displays correctly before the first canonical save.
 from modules.config_schema import LEGACY_ENABLED_ALIASES as _ENABLED_LEGACY_ALIASES
 
-VALID_TYPES = {"bool", "int", "float", "str", "enum", "list"}
+VALID_TYPES = {"bool", "int", "float", "str", "enum", "list", "password"}
 
 # Truthy/falsey string forms accepted for bool fields (configparser-compatible).
 _TRUE = {"1", "true", "yes", "on"}
@@ -122,7 +122,8 @@ def validate_field(field: dict, raw: Any) -> tuple[bool, Any, Optional[str]]:
                     return False, None, f"{label} contains an invalid value: {item}"
         return True, items, None
 
-    # str (default)
+    # str / password (password is a str stored in plaintext in config.ini,
+    # masked only in the web UI — same validation as str)
     s = str(raw)
     pattern = field.get("pattern")
     if pattern and not re.fullmatch(pattern, s):
@@ -330,6 +331,12 @@ def _assemble_entry(
             continue
         resolved = dict(field)
         resolved["value"] = _read_typed(config, section, field)
+        if field.get("type") == "password":
+            # Never send the plaintext secret to the browser; the UI shows a
+            # placeholder when has_value is true and only submits a new value
+            # if the user actually types one.
+            resolved["has_value"] = bool(resolved["value"])
+            resolved["value"] = ""
         fields.append(resolved)
 
     # Every command can restrict which channels it responds in

modules/web_viewer/templates/plugins.html

@@ -600,6 +600,36 @@ function renderField(field, overrideValue) {
         wrapper.appendChild(group);
         if (field.help) wrapper.appendChild(helpText(field.help));
         return { wrapper, input };
+    } else if (field.type === 'password') {
+        const group = document.createElement('div');
+        group.className = 'input-group input-group-sm has-validation';
+        input = document.createElement('input');
+        input.className = 'form-control';
+        input.type = 'password';
+        input.autocomplete = 'new-password';
+        if (field.pattern) input.pattern = field.pattern;
+        input.value = (value !== undefined && value !== null) ? value : '';
+        input.placeholder = field.has_value ? '(saved — enter new value to change)' : '';
+        group.appendChild(input);
+        const toggleBtn = document.createElement('button');
+        toggleBtn.type = 'button';
+        toggleBtn.className = 'btn btn-outline-secondary';
+        const toggleIcon = document.createElement('i');
+        toggleIcon.className = 'fas fa-eye';
+        toggleBtn.appendChild(toggleIcon);
+        toggleBtn.addEventListener('click', () => {
+            const showing = input.type === 'text';
+            input.type = showing ? 'password' : 'text';
+            toggleIcon.classList.toggle('fa-eye', showing);
+            toggleIcon.classList.toggle('fa-eye-slash', !showing);
+        });
+        group.appendChild(toggleBtn);
+        const fb = document.createElement('div');
+        fb.className = 'invalid-feedback';
+        group.appendChild(fb);
+        wrapper.appendChild(group);
+        if (field.help) wrapper.appendChild(helpText(field.help));
+        return { wrapper, input };
     } else {
         input = document.createElement('input');
         input.className = 'form-control form-control-sm';
@@ -638,7 +668,7 @@ function fieldColClass(field) {
     if (field.type === 'int' || field.type === 'float' || field.type === 'enum') {
         return 'col-6 col-md-4 col-xl-3';
     }
-    return 'col-12 col-sm-6 col-xl-4';  // str / list — medium
+    return 'col-12 col-sm-6 col-xl-4';  // str / list / password — medium
 }
 
 // Badge marking a field that reads/writes a shared section (not the plugin's own).
@@ -870,6 +900,7 @@ function validateClient(field, raw) {
     const empty = (raw === '' || raw === null || raw === undefined);
     if (field.type === 'bool') return null;
     if (empty) {
+        if (field.type === 'password' && field.has_value) return null;  // leave unchanged
         return field.required ? `${field.label} is required` : null;
     }
     if (field.type === 'int' || field.type === 'float') {
@@ -883,7 +914,7 @@ function validateClient(field, raw) {
         const allowed = (field.options || []).map(o => String(o.value));
         if (!allowed.includes(String(raw))) return `${field.label} is invalid`;
     }
-    if (field.type === 'str' && field.pattern) {
+    if ((field.type === 'str' || field.type === 'password') && field.pattern) {
         if (!new RegExp('^(?:' + field.pattern + ')$').test(raw)) return `${field.label} has an invalid format`;
     }
     return null;