Upgrade Holepunch P2P stack and npm dependencies

Align p2ns with current Holepunch ecosystem versions: autopass 3,
hyperdb 6, hyperschema 1.21, hyperdrive 13, corestore 7.10, hyperswarm
4.17, protomux 3.11, and compact-encoding 3 (with npm overrides).
Also bump Tailwind/PostCSS, ws, node-forge, and related tooling; add
express and holesail-logger; remove unused install/npm packages.

Use cache/plugin-spec when plugin spec dirs are not writable, and
update docs and proxy install notes. Rebuild admin CSS for Tailwind 4.3.

Existing P2P storage must be wiped (--clean) after upgrading.

includes/plugins/db-manager.js

@@ -153,10 +153,10 @@ async function getDatabase(pluginDomain, pluginDir, dbDir) {
       logError('DBManager', `Database definition file does not exist: ${defPath}`);
       logError('DBManager', `This means HyperDB schemas were not built successfully.`);
       logError('DBManager', `Solutions:`);
-      logError('DBManager', `1. Delete plugin-sites/${pluginDomain}/spec/ directory and restart P2NS`);
+      logError('DBManager', `1. Delete plugin-sites/${pluginDomain}/spec/ or cache/plugin-spec/${pluginDomain}/ and restart P2NS`);
       logError('DBManager', `2. Check plugin config.json has valid hyperdb configuration`);
       logError('DBManager', `3. Verify schema builder has required dependencies installed`);
-      throw new Error(`Database definition file not found at ${defPath}. HyperDB schemas need to be built. Try: rm -rf plugin-sites/${pluginDomain}/spec/ && restart P2NS`);
+      throw new Error(`Database definition file not found at ${defPath}. HyperDB schemas need to be built. Try: rm -rf plugin-sites/${pluginDomain}/spec/ cache/plugin-spec/${pluginDomain}/ && restart P2NS`);
     }
     
     let def;

includes/plugins/hyperdb-builder.js

@@ -8,9 +8,46 @@
 const Hyperschema = require('hyperschema');
 const HyperDBBuilder = require('hyperdb/builder');
 const fs = require('fs').promises;
+const fsSync = require('fs');
 const path = require('path');
 const { logDebug, logError, logInfo, logWarn } = require('../infrastructure/logger');
 
+const PROJECT_ROOT = path.resolve(__dirname, '../..');
+
+/**
+ * Resolve writable spec directories (plugin dir or cache fallback).
+ * @param {string} pluginDir - Plugin directory path
+ * @param {Object} config - Plugin config object
+ * @returns {{ schemaDir: string, dbDir: string }}
+ */
+function resolveSpecDirs(pluginDir, config) {
+  const pluginDomain = config.domain || path.basename(pluginDir);
+  const inPluginSpec = path.join(pluginDir, 'spec');
+
+  const isWritable = (dir) => {
+    try {
+      fsSync.accessSync(dir, fsSync.constants.W_OK);
+      return true;
+    } catch {
+      return false;
+    }
+  };
+
+  let specBase = inPluginSpec;
+  if (!isWritable(pluginDir) || (fsSync.existsSync(inPluginSpec) && !isWritable(inPluginSpec))) {
+    specBase = path.join(PROJECT_ROOT, 'cache', 'plugin-spec', pluginDomain, 'spec');
+    logInfo(
+      'HyperDBBuilder',
+      `Using cache spec path for ${pluginDomain} (plugin spec dir not writable): ${specBase}`
+    );
+  }
+
+  return {
+    schemaDir: path.join(specBase, 'hyperschema'),
+    dbDir: path.join(specBase, 'hyperdb')
+  };
+}
+
 /**
  * Build HyperDB schemas and definitions from plugin config
  * @param {string} pluginDir - Plugin directory path
@@ -23,8 +60,7 @@ async function buildSchemaFromConfig(pluginDir, config) {
   }
 
   const hyperdbConfig = config.hyperdb;
-  const schemaDir = path.join(pluginDir, 'spec', 'hyperschema');
-  const dbDir = path.join(pluginDir, 'spec', 'hyperdb');
+  const { schemaDir, dbDir } = resolveSpecDirs(pluginDir, config);
 
   // Ensure directories exist
   await fs.mkdir(schemaDir, { recursive: true });
@@ -208,8 +244,7 @@ async function needsRebuild(pluginDir, config) {
     return false;
   }
 
-  const schemaDir = path.join(pluginDir, 'spec', 'hyperschema');
-  const dbDir = path.join(pluginDir, 'spec', 'hyperdb');
+  const { schemaDir, dbDir } = resolveSpecDirs(pluginDir, config);
 
   try {
     // Check if directories exist
@@ -252,10 +287,7 @@ async function ensureSchemaBuilt(pluginDir, config) {
     return await buildSchemaFromConfig(pluginDir, config);
   }
 
-  const schemaDir = path.join(pluginDir, 'spec', 'hyperschema');
-  const dbDir = path.join(pluginDir, 'spec', 'hyperdb');
-
-  return { schemaDir, dbDir };
+  return resolveSpecDirs(pluginDir, config);
 }
 
 module.exports = {
@@ -263,6 +295,7 @@ module.exports = {
   buildHyperschema,
   buildHyperDBDefinition,
   needsRebuild,
-  ensureSchemaBuilt
+  ensureSchemaBuilt,
+  resolveSpecDirs
 };