feat(share): "Biz Connect" in the iOS share sheet — share a photo/file into a chat

Adds the reverse direction: share FROM Photos/Files/Safari INTO a Biz Connect
conversation. An app can only appear in the iOS share sheet as an app-extension
target, so this is real native work, not a web change.

Pieces:
- mobile/ios-share/ShareViewController.swift: a UI-less Share Extension. It stages
  the shared items into the App Group container and opens bizconnect://share. It
  deliberately does NOT reimplement the chat picker — that lives in the app, which
  already has the chat list, search and upload progress. Appends to the manifest
  (never overwrites), so sharing twice before opening the app loses nothing.
- mobile/scripts/add-share-extension.rb: injects the extension target into the
  Capacitor-generated Xcode project on every CI build (Codemagic checks out fresh),
  using the xcodeproj gem that ships with CocoaPods. Embeds it, sets the bundle id
  <app>.share, and MERGES the App Group into the app's entitlements rather than
  clobbering them (push's aps-environment must survive). Idempotent.
- mobile/plugins/share-inbox: getPending()/clear() to read that manifest — the App
  Group container isn't one of Filesystem's known directories, so it needs a bridge.
- home.html: on bizconnect://share (and every resume, and cold-launch), read the
  inbox and show a "Send to…" picker over the chat list; chosen files run the SAME
  upload + /api/messages send as an in-app attachment. Reuses convertFileSrc to read
  the staged bytes with no base64 marshalling.
- ios-patch.sh registers the bizconnect URL scheme; codemagic.yaml fetches a profile
  for the .share bundle id too.

One-time manual gate (CI cannot toggle App capabilities): the App Group
group.com.bizgaze.connect must be created and enabled on both App IDs in the Apple
portal — documented in mobile/IOS_SETUP.md. Without it the two processes can't see
each other's files and sharing silently no-ops; everything else still works.

Validated cross-file: pod-name/jsName/method wiring for all three plugins, App
Group id identical in all 4 files, URL scheme consistent across extension/plist/web,
entitlement-merge preserves push. Needs a new iOS build (new targets + plugins).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

mobile/ios-share/Info.plist

@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>$(DEVELOPMENT_LANGUAGE)</string>
+	<key>CFBundleDisplayName</key>
+	<string>Biz Connect</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>XPC!</string>
+	<key>CFBundleShortVersionString</key>
+	<string>$(MARKETING_VERSION)</string>
+	<key>CFBundleVersion</key>
+	<string>$(CURRENT_PROJECT_VERSION)</string>
+	<key>NSExtension</key>
+	<dict>
+		<key>NSExtensionPointIdentifier</key>
+		<string>com.apple.share-services</string>
+		<!-- No storyboard: the extension has no UI of its own (see ShareViewController). -->
+		<key>NSExtensionPrincipalClass</key>
+		<string>$(PRODUCT_MODULE_NAME).ShareViewController</string>
+		<key>NSExtensionAttributes</key>
+		<dict>
+			<!-- What Biz Connect offers to accept from the share sheet. Without a matching rule here the
+			     app simply does not appear for that content type. -->
+			<key>NSExtensionActivationRule</key>
+			<dict>
+				<key>NSExtensionActivationSupportsImageWithMaxCount</key>
+				<integer>20</integer>
+				<key>NSExtensionActivationSupportsMovieWithMaxCount</key>
+				<integer>10</integer>
+				<key>NSExtensionActivationSupportsFileWithMaxCount</key>
+				<integer>20</integer>
+				<key>NSExtensionActivationSupportsWebURLWithMaxCount</key>
+				<integer>1</integer>
+				<key>NSExtensionActivationSupportsText</key>
+				<true/>
+			</dict>
+		</dict>
+	</dict>
+</dict>
+</plist>