Prevent duplicate approve reviews + redesign bottom bar; bump to 2.9

- Approve: rapid taps fired multiple submitReview calls that each appended a
  review, stacking duplicate entries. Add a busy guard (skip while one is in
  flight) and dedupe reviews per user so the latest replaces earlier ones;
  disable the review menu while submitting.
- Bottom bar: replace the full-width bar with a floating frosted-glass pill
  inset from the edges (like SideStore), with a highlighted capsule behind
  the active tab. Bump to 2.9.

GiteaPR.xcodeproj/project.pbxproj

@@ -187,7 +187,7 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 19;
+				CURRENT_PROJECT_VERSION = 20;
 				DEVELOPMENT_TEAM = "";
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_KEY_CFBundleDisplayName = "GiteaPR";
@@ -197,7 +197,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 2.8;
+				MARKETING_VERSION = 2.9;
 				PRODUCT_BUNDLE_IDENTIFIER = com.bueso.giteapr;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = YES;
@@ -211,7 +211,7 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 19;
+				CURRENT_PROJECT_VERSION = 20;
 				DEVELOPMENT_TEAM = "";
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_KEY_CFBundleDisplayName = "GiteaPR";
@@ -221,7 +221,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 2.8;
+				MARKETING_VERSION = 2.9;
 				PRODUCT_BUNDLE_IDENTIFIER = com.bueso.giteapr;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = YES;