diff --git a/.ruby-version b/.ruby-version
index a0891f5..84d6c67 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.3.4
+3.4.10
diff --git a/Gemfile b/Gemfile
index 9b3924d..e00eeee 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,10 +3,18 @@
 source 'https://rubygems.org'
 git_source(:github) {|_repo| "https://github.com/#{repo}.git" }
 
-ruby '3.3.4'
+ruby '3.4.10'
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails', branch: 'main'
-gem 'rails', '~> 7.2.1'
+gem 'rails', '~> 8.1.3'
+
+# csv stopped being a Ruby default gem in 3.4+; httparty requires it internally
+# without declaring it as a dependency, so it must be explicit here.
+gem 'csv'
+
+# benchmark won't be a default gem starting in Ruby 4.0; mini_magick requires it
+# internally without declaring it as a dependency.
+gem 'benchmark'
 
 # Use postgresql as the database for Active Record
 gem 'pg', '~> 1.1'
@@ -68,7 +76,11 @@ gem 'kaminari', '~> 1.2'
 
 gem 'jbuilder', '~> 2.11'
 
-gem 'acts-as-taggable-on', '~> 11.0.0'
+# 11.0.0 hard-pins activerecord < 8.0, which makes it impossible to install
+# alongside Rails 8 at all - not a discretionary bump, a forced one. 12->13 has
+# no breaking changes to the tag_list/for_context API ActsAsTaggableField uses
+# (see CHANGELOG.md), only dropped-Ruby-version and added-Rails-version support.
+gem 'acts-as-taggable-on', '~> 13.0'
 
 gem 'administrate-field-list', '~> 0.0.6'
 
@@ -84,7 +96,7 @@ gem 'active_record_doctor', '~> 1.10'
 
 gem 'sidekiq', '>=7.2.2', '<8'
 
-gem 'addressable', '~> 2.8'
+gem 'addressable', '~> 2.9'
 
 gem 'importmap-rails', '~> 2.0'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index a5c643d..3b4bc5b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,83 +1,87 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    actioncable (7.2.1)
-      actionpack (= 7.2.1)
-      activesupport (= 7.2.1)
+    action_text-trix (2.1.19)
+      railties
+    actioncable (8.1.3.1)
+      actionpack (= 8.1.3.1)
+      activesupport (= 8.1.3.1)
       nio4r (~> 2.0)
       websocket-driver (>= 0.6.1)
       zeitwerk (~> 2.6)
-    actionmailbox (7.2.1)
-      actionpack (= 7.2.1)
-      activejob (= 7.2.1)
-      activerecord (= 7.2.1)
-      activestorage (= 7.2.1)
-      activesupport (= 7.2.1)
+    actionmailbox (8.1.3.1)
+      actionpack (= 8.1.3.1)
+      activejob (= 8.1.3.1)
+      activerecord (= 8.1.3.1)
+      activestorage (= 8.1.3.1)
+      activesupport (= 8.1.3.1)
       mail (>= 2.8.0)
-    actionmailer (7.2.1)
-      actionpack (= 7.2.1)
-      actionview (= 7.2.1)
-      activejob (= 7.2.1)
-      activesupport (= 7.2.1)
+    actionmailer (8.1.3.1)
+      actionpack (= 8.1.3.1)
+      actionview (= 8.1.3.1)
+      activejob (= 8.1.3.1)
+      activesupport (= 8.1.3.1)
       mail (>= 2.8.0)
       rails-dom-testing (~> 2.2)
-    actionpack (7.2.1)
-      actionview (= 7.2.1)
-      activesupport (= 7.2.1)
+    actionpack (8.1.3.1)
+      actionview (= 8.1.3.1)
+      activesupport (= 8.1.3.1)
       nokogiri (>= 1.8.5)
-      racc
-      rack (>= 2.2.4, < 3.2)
+      rack (>= 2.2.4)
       rack-session (>= 1.0.1)
       rack-test (>= 0.6.3)
       rails-dom-testing (~> 2.2)
       rails-html-sanitizer (~> 1.6)
       useragent (~> 0.16)
-    actiontext (7.2.1)
-      actionpack (= 7.2.1)
-      activerecord (= 7.2.1)
-      activestorage (= 7.2.1)
-      activesupport (= 7.2.1)
+    actiontext (8.1.3.1)
+      action_text-trix (~> 2.1.15)
+      actionpack (= 8.1.3.1)
+      activerecord (= 8.1.3.1)
+      activestorage (= 8.1.3.1)
+      activesupport (= 8.1.3.1)
       globalid (>= 0.6.0)
       nokogiri (>= 1.8.5)
-    actionview (7.2.1)
-      activesupport (= 7.2.1)
+    actionview (8.1.3.1)
+      activesupport (= 8.1.3.1)
       builder (~> 3.1)
       erubi (~> 1.11)
       rails-dom-testing (~> 2.2)
       rails-html-sanitizer (~> 1.6)
     active_record_doctor (1.14.0)
       activerecord (>= 4.2.0)
-    activejob (7.2.1)
-      activesupport (= 7.2.1)
+    activejob (8.1.3.1)
+      activesupport (= 8.1.3.1)
       globalid (>= 0.3.6)
-    activemodel (7.2.1)
-      activesupport (= 7.2.1)
-    activerecord (7.2.1)
-      activemodel (= 7.2.1)
-      activesupport (= 7.2.1)
+    activemodel (8.1.3.1)
+      activesupport (= 8.1.3.1)
+    activerecord (8.1.3.1)
+      activemodel (= 8.1.3.1)
+      activesupport (= 8.1.3.1)
       timeout (>= 0.4.0)
-    activestorage (7.2.1)
-      actionpack (= 7.2.1)
-      activejob (= 7.2.1)
-      activerecord (= 7.2.1)
-      activesupport (= 7.2.1)
+    activestorage (8.1.3.1)
+      actionpack (= 8.1.3.1)
+      activejob (= 8.1.3.1)
+      activerecord (= 8.1.3.1)
+      activesupport (= 8.1.3.1)
       marcel (~> 1.0)
-    activesupport (7.2.1)
+    activesupport (8.1.3.1)
       base64
       bigdecimal
       concurrent-ruby (~> 1.0, >= 1.3.1)
       connection_pool (>= 2.2.5)
       drb
       i18n (>= 1.6, < 2)
+      json
       logger (>= 1.4.2)
       minitest (>= 5.1)
       securerandom (>= 0.3)
       tzinfo (~> 2.0, >= 2.0.5)
-    acts-as-taggable-on (11.0.0)
-      activerecord (>= 7.0, < 8.0)
+      uri (>= 0.13.1)
+    acts-as-taggable-on (13.0.0)
+      activerecord (>= 7.1, < 8.2)
       zeitwerk (>= 2.4, < 3.0)
-    addressable (2.8.7)
-      public_suffix (>= 2.0.2, < 7.0)
+    addressable (2.9.0)
+      public_suffix (>= 2.0.2, < 8.0)
     administrate (1.0.0)
       actionpack (>= 6.0, < 9.0)
       actionview (>= 6.0, < 9.0)
@@ -92,7 +96,7 @@ GEM
     administrate-field-list (0.0.6)
       administrate
       rails (>= 5.0)
-    ast (2.4.2)
+    ast (2.4.3)
     aws-eventstream (1.4.0)
     aws-partitions (1.1278.0)
     aws-sdk-core (3.254.1)
@@ -111,9 +115,10 @@ GEM
       aws-sigv4 (~> 1.5)
     aws-sigv4 (1.12.1)
       aws-eventstream (~> 1, >= 1.0.2)
-    base64 (0.2.0)
-    bigdecimal (3.1.8)
-    bootsnap (1.18.4)
+    base64 (0.3.0)
+    benchmark (0.5.0)
+    bigdecimal (3.1.9)
+    bootsnap (1.18.6)
       msgpack (~> 1.2)
     builder (3.3.0)
     capybara (3.40.0)
@@ -125,19 +130,20 @@ GEM
       rack-test (>= 0.6.3)
       regexp_parser (>= 1.5, < 3.0)
       xpath (~> 3.2)
-    concurrent-ruby (1.3.4)
+    concurrent-ruby (1.3.8)
     connection_pool (2.4.1)
-    crass (1.0.6)
+    crass (1.0.7)
     cronex (0.15.0)
       tzinfo
       unicode (>= 0.4.4.5)
-    date (3.3.4)
+    csv (3.3.6)
+    date (3.5.1)
     debug (1.9.2)
       irb (~> 1.10)
       reline (>= 0.3.8)
     diff-lcs (1.5.1)
-    drb (2.2.1)
-    elastic-transport (8.5.2)
+    drb (2.2.3)
+    elastic-transport (8.5.3)
       faraday (< 3)
       multi_json
     elasticsearch (8.19.3)
@@ -146,33 +152,33 @@ GEM
       ostruct
     elasticsearch-api (8.19.3)
       multi_json
-    erubi (1.13.0)
-    et-orbi (1.4.0)
+    erubi (1.13.1)
+    et-orbi (1.4.1)
       tzinfo
-    factory_bot (6.4.6)
-      activesupport (>= 5.0.0)
-    factory_bot_rails (6.4.3)
-      factory_bot (~> 6.4)
+    factory_bot (6.5.6)
+      activesupport (>= 6.1.0)
+    factory_bot_rails (6.4.4)
+      factory_bot (~> 6.5)
       railties (>= 5.0.0)
     faker (3.4.2)
       i18n (>= 1.8.11, < 2)
-    faraday (2.14.2)
+    faraday (2.14.3)
       faraday-net_http (>= 2.0, < 3.5)
       json
       logger
     faraday-net_http (3.4.4)
       net-http (~> 0.5)
-    ffi (1.17.0-aarch64-linux-gnu)
-    ffi (1.17.0-aarch64-linux-musl)
-    ffi (1.17.0-arm-linux-gnu)
-    ffi (1.17.0-arm-linux-musl)
-    ffi (1.17.0-arm64-darwin)
-    ffi (1.17.0-x86-linux-gnu)
-    ffi (1.17.0-x86-linux-musl)
-    ffi (1.17.0-x86_64-darwin)
-    ffi (1.17.0-x86_64-linux-gnu)
-    ffi (1.17.0-x86_64-linux-musl)
-    fugit (1.12.2)
+    ffi (1.17.4-aarch64-linux-gnu)
+    ffi (1.17.4-aarch64-linux-musl)
+    ffi (1.17.4-arm-linux-gnu)
+    ffi (1.17.4-arm-linux-musl)
+    ffi (1.17.4-arm64-darwin)
+    ffi (1.17.4-x86-linux-gnu)
+    ffi (1.17.4-x86-linux-musl)
+    ffi (1.17.4-x86_64-darwin)
+    ffi (1.17.4-x86_64-linux-gnu)
+    ffi (1.17.4-x86_64-linux-musl)
+    fugit (1.12.3)
       et-orbi (~> 1.4)
       raabro (~> 1.4)
     globalid (1.2.1)
@@ -181,24 +187,24 @@ GEM
     httparty (0.20.0)
       mime-types (~> 3.0)
       multi_xml (>= 0.5.2)
-    i18n (1.14.5)
+    i18n (1.14.8)
       concurrent-ruby (~> 1.0)
     image_processing (1.13.0)
       mini_magick (>= 4.9.5, < 5)
       ruby-vips (>= 2.0.17, < 3)
-    importmap-rails (2.0.1)
+    importmap-rails (2.0.3)
       actionpack (>= 6.0.0)
       activesupport (>= 6.0.0)
       railties (>= 6.0.0)
     io-console (0.7.2)
-    irb (1.14.0)
+    irb (1.14.3)
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
     jbuilder (2.12.0)
       actionview (>= 5.0.0)
       activesupport (>= 5.0.0)
     jmespath (1.6.2)
-    json (2.7.2)
+    json (2.7.6)
     kaminari (1.2.2)
       activesupport (>= 4.1.0)
       kaminari-actionview (= 1.2.2)
@@ -211,105 +217,115 @@ GEM
       activerecord
       kaminari-core (= 1.2.2)
     kaminari-core (1.2.2)
-    language_server-protocol (3.17.0.3)
-    logger (1.6.0)
-    loofah (2.22.0)
+    language_server-protocol (3.17.0.6)
+    logger (1.6.6)
+    loofah (2.25.2)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
-    mail (2.8.1)
+    mail (2.9.1)
+      logger
       mini_mime (>= 0.1.1)
       net-imap
       net-pop
       net-smtp
-    marcel (1.0.4)
+    marcel (1.2.1)
     matrix (0.4.3)
     mime-types (3.5.2)
       mime-types-data (~> 3.2015)
-    mime-types-data (3.2024.0820)
+    mime-types-data (3.2024.1203)
     mini_magick (4.13.2)
     mini_mime (1.1.5)
-    minitest (5.25.1)
-    msgpack (1.7.2)
+    mini_portile2 (2.8.9)
+    minitest (5.25.5)
+    msgpack (1.8.4)
     multi_json (1.21.1)
-    multi_xml (0.7.1)
+    multi_xml (0.7.2)
       bigdecimal (~> 3.1)
     namae (1.2.0)
       racc (~> 1.7)
     net-http (0.9.1)
       uri (>= 0.11.1)
-    net-imap (0.4.14)
+    net-imap (0.6.6)
       date
       net-protocol
     net-pop (0.1.2)
       net-protocol
     net-protocol (0.2.2)
       timeout
-    net-smtp (0.5.0)
+    net-smtp (0.5.1)
       net-protocol
-    nio4r (2.7.3)
-    nokogiri (1.16.7-aarch64-linux)
+    nio4r (2.7.5)
+    nokogiri (1.19.4)
+      mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
-    nokogiri (1.16.7-arm-linux)
+    nokogiri (1.19.4-aarch64-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.16.7-arm64-darwin)
+    nokogiri (1.19.4-aarch64-linux-musl)
       racc (~> 1.4)
-    nokogiri (1.16.7-x86-linux)
+    nokogiri (1.19.4-arm-linux-gnu)
       racc (~> 1.4)
-    nokogiri (1.16.7-x86_64-darwin)
+    nokogiri (1.19.4-arm-linux-musl)
       racc (~> 1.4)
-    nokogiri (1.16.7-x86_64-linux)
+    nokogiri (1.19.4-arm64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.19.4-x86_64-darwin)
+      racc (~> 1.4)
+    nokogiri (1.19.4-x86_64-linux-gnu)
+      racc (~> 1.4)
+    nokogiri (1.19.4-x86_64-linux-musl)
       racc (~> 1.4)
     ostruct (0.6.3)
     parallel (1.26.3)
-    parser (3.3.4.2)
+    parser (3.3.12.0)
       ast (~> 2.4.1)
       racc
-    pg (1.5.7)
+    pg (1.5.9)
     psych (5.1.2)
       stringio
-    public_suffix (6.0.1)
-    puma (5.6.8)
+    public_suffix (7.0.5)
+    puma (5.6.9)
       nio4r (~> 2.0)
     raabro (1.4.0)
     racc (1.8.1)
-    rack (2.2.9)
+    rack (2.2.23)
     rack-cors (2.0.2)
       rack (>= 2.0.0)
     rack-session (1.0.2)
       rack (< 3)
     rack-test (2.1.0)
       rack (>= 1.3)
-    rackup (1.0.0)
+    rackup (1.0.1)
       rack (< 3)
       webrick
-    rails (7.2.1)
-      actioncable (= 7.2.1)
-      actionmailbox (= 7.2.1)
-      actionmailer (= 7.2.1)
-      actionpack (= 7.2.1)
-      actiontext (= 7.2.1)
-      actionview (= 7.2.1)
-      activejob (= 7.2.1)
-      activemodel (= 7.2.1)
-      activerecord (= 7.2.1)
-      activestorage (= 7.2.1)
-      activesupport (= 7.2.1)
+    rails (8.1.3.1)
+      actioncable (= 8.1.3.1)
+      actionmailbox (= 8.1.3.1)
+      actionmailer (= 8.1.3.1)
+      actionpack (= 8.1.3.1)
+      actiontext (= 8.1.3.1)
+      actionview (= 8.1.3.1)
+      activejob (= 8.1.3.1)
+      activemodel (= 8.1.3.1)
+      activerecord (= 8.1.3.1)
+      activestorage (= 8.1.3.1)
+      activesupport (= 8.1.3.1)
       bundler (>= 1.15.0)
-      railties (= 7.2.1)
+      railties (= 8.1.3.1)
     rails-dom-testing (2.2.0)
       activesupport (>= 5.0.0)
       minitest
       nokogiri (>= 1.6)
-    rails-html-sanitizer (1.6.0)
-      loofah (~> 2.21)
-      nokogiri (~> 1.14)
-    railties (7.2.1)
-      actionpack (= 7.2.1)
-      activesupport (= 7.2.1)
+    rails-html-sanitizer (1.7.1)
+      loofah (~> 2.25, >= 2.25.2)
+      nokogiri (>= 1.15.7, != 1.16.7, != 1.16.6, != 1.16.5, != 1.16.4, != 1.16.3, != 1.16.2, != 1.16.1, != 1.16.0.rc1, != 1.16.0)
+    railties (8.1.3.1)
+      actionpack (= 8.1.3.1)
+      activesupport (= 8.1.3.1)
       irb (~> 1.13)
       rackup (>= 1.0.0)
       rake (>= 12.2)
       thor (~> 1.0, >= 1.2.2)
+      tsort (>= 0.2)
       zeitwerk (~> 2.6)
     rainbow (3.1.1)
     rake (13.2.1)
@@ -317,23 +333,22 @@ GEM
       psych (>= 4.0.0)
     redis-client (0.23.2)
       connection_pool
-    regexp_parser (2.9.2)
-    reline (0.5.9)
+    regexp_parser (2.9.3)
+    reline (0.5.12)
       io-console (~> 0.5)
-    rexml (3.3.6)
-      strscan
+    rexml (3.4.4)
     roo (2.10.1)
       nokogiri (~> 1)
       rubyzip (>= 1.3.0, < 3.0.0)
-    rspec-core (3.13.0)
+    rspec-core (3.13.6)
       rspec-support (~> 3.13.0)
-    rspec-expectations (3.13.2)
+    rspec-expectations (3.13.5)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-mocks (3.13.1)
+    rspec-mocks (3.13.8)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.13.0)
-    rspec-rails (6.1.4)
+    rspec-rails (6.1.5)
       actionpack (>= 6.1)
       activesupport (>= 6.1)
       railties (>= 6.1)
@@ -341,7 +356,7 @@ GEM
       rspec-expectations (~> 3.13)
       rspec-mocks (~> 3.13)
       rspec-support (~> 3.13)
-    rspec-support (3.13.1)
+    rspec-support (3.13.7)
     rubocop (1.65.1)
       json (~> 2.3)
       language_server-protocol (>= 3.17.0)
@@ -353,22 +368,22 @@ GEM
       rubocop-ast (>= 1.31.1, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 3.0)
-    rubocop-ast (1.32.1)
+    rubocop-ast (1.32.3)
       parser (>= 3.3.1.0)
     rubocop-factory_bot (2.26.1)
       rubocop (~> 1.61)
-    rubocop-rails (2.26.0)
+    rubocop-rails (2.26.2)
       activesupport (>= 4.2.0)
       rack (>= 1.1)
       rubocop (>= 1.52.0, < 2.0)
       rubocop-ast (>= 1.31.1, < 2.0)
-    rubocop-rspec (3.0.4)
+    rubocop-rspec (3.0.5)
       rubocop (~> 1.61)
     rubocop-rspec_rails (2.30.0)
       rubocop (~> 1.61)
       rubocop-rspec (~> 3, >= 3.0.1)
     ruby-progressbar (1.13.0)
-    ruby-vips (2.2.2)
+    ruby-vips (2.2.5)
       ffi (~> 1.12)
       logger
     rubyzip (2.3.2)
@@ -383,7 +398,7 @@ GEM
     searchkick (5.3.1)
       activemodel (>= 6.1)
       hashie
-    securerandom (0.3.1)
+    securerandom (0.3.2)
     selenium-devtools (0.151.0)
       selenium-webdriver (~> 4.2)
     selenium-webdriver (4.46.0)
@@ -394,12 +409,12 @@ GEM
       websocket (~> 1.0)
     shoulda-matchers (6.4.0)
       activesupport (>= 5.2.0)
-    sidekiq (7.3.8)
+    sidekiq (7.3.10)
       base64
-      connection_pool (>= 2.3.0)
+      connection_pool (>= 2.3.0, < 3)
       logger
-      rack (>= 2.2.4)
-      redis-client (>= 0.22.2)
+      rack (>= 2.2.4, < 3.3)
+      redis-client (>= 0.23.0, < 1)
     sidekiq-cron (2.4.0)
       cronex (>= 0.13.0)
       fugit (~> 1.8, >= 1.11.1)
@@ -413,27 +428,28 @@ GEM
       actionpack (>= 6.1)
       activesupport (>= 6.1)
       sprockets (>= 3.0.0)
-    stringio (3.1.1)
-    strscan (3.1.0)
-    thor (1.3.1)
+    stringio (3.1.9)
+    thor (1.3.2)
     tilt (2.8.0)
-    timeout (0.4.1)
+    timeout (0.6.1)
     trix-rails (2.4.0)
       rails (> 4.1)
+    tsort (0.2.0)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
     unicode (0.4.4.5)
     unicode-display_width (2.5.0)
     uri (1.1.1)
-    useragent (0.16.10)
-    webrick (1.8.1)
+    useragent (0.16.11)
+    webrick (1.8.2)
     websocket (1.2.11)
-    websocket-driver (0.7.6)
+    websocket-driver (0.8.2)
+      base64
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
     xpath (3.2.0)
       nokogiri (~> 1.8)
-    zeitwerk (2.6.17)
+    zeitwerk (2.6.18)
 
 PLATFORMS
   aarch64-linux
@@ -452,16 +468,18 @@ PLATFORMS
 
 DEPENDENCIES
   active_record_doctor (~> 1.10)
-  acts-as-taggable-on (~> 11.0.0)
-  addressable (~> 2.8)
+  acts-as-taggable-on (~> 13.0)
+  addressable (~> 2.9)
   administrate
   administrate-field-active_storage (~> 0.4.1)
   administrate-field-jsonb
   administrate-field-list (~> 0.0.6)
   aws-sdk-rails (~> 5.0)
   aws-sdk-ses (~> 1.0)
+  benchmark
   bootsnap
   capybara
+  csv
   debug
   elasticsearch (~> 8)
   factory_bot_rails
@@ -475,7 +493,7 @@ DEPENDENCIES
   pg (~> 1.1)
   puma (~> 5.0)
   rack-cors
-  rails (~> 7.2.1)
+  rails (~> 8.1.3)
   roo (~> 2.9)
   rspec-rails
   rubocop
@@ -495,7 +513,7 @@ DEPENDENCIES
   tzinfo-data
 
 RUBY VERSION
-   ruby 3.3.4p94
+   ruby 3.4.10p104
 
 BUNDLED WITH
    2.5.11
diff --git a/app/fields/acts_as_taggable_field.rb b/app/fields/acts_as_taggable_field.rb
index 528a3a3..ca78488 100644
--- a/app/fields/acts_as_taggable_field.rb
+++ b/app/fields/acts_as_taggable_field.rb
@@ -18,6 +18,22 @@ def context
     options.fetch(:context, @attribute)
   end
 
+  # Administrate::Field::Base#read_value (called from #initialize, before
+  # #attribute is overridden below has a chance to matter) lazily fetches data via
+  # `resource.try(attribute)` - and that `attribute` call is polymorphic, so it hits
+  # our own override below instead of the raw `:tags` attribute key, fetching
+  # `resource.tag_list` (an array of tag-name strings) instead of `resource.tags`
+  # (real ActsAsTaggableOn::Tag records). #tags/#delimited/#truncate all expect the
+  # latter, so this re-derives the same logic using @attribute (the raw ivar) rather
+  # than the overridden #attribute method.
+  def read_value(data)
+    if options.key?(:getter)
+      return options[:getter].respond_to?(:call) ? options[:getter].call(self) : resource.try(options[:getter])
+    end
+
+    data.nil? ? resource.try(@attribute) : data
+  end
+
   # acts_as_taggable_on exposes a `<context.singularize>_list` virtual attribute
   # (e.g. `tag_list` for the `:tags` context) for reading/writing a comma-delimited
   # tag string - this field operates on that attribute rather than the raw `tags`
diff --git a/app/workers/resave_all_letters_worker.rb b/app/workers/resave_all_letters_worker.rb
index a84ef58..5d95750 100644
--- a/app/workers/resave_all_letters_worker.rb
+++ b/app/workers/resave_all_letters_worker.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ResaveAllLettersWorker
   include Sidekiq::Job
 
diff --git a/bin/dev b/bin/dev
new file mode 100644
index 0000000..5f91c20
--- /dev/null
+++ b/bin/dev
@@ -0,0 +1,2 @@
+#!/usr/bin/env ruby
+exec "./bin/rails", "server", *ARGV
diff --git a/bin/rubocop b/bin/rubocop
new file mode 100644
index 0000000..5a20504
--- /dev/null
+++ b/bin/rubocop
@@ -0,0 +1,8 @@
+#!/usr/bin/env ruby
+require "rubygems"
+require "bundler/setup"
+
+# Explicit RuboCop config increases performance slightly while avoiding config confusion.
+ARGV.unshift("--config", File.expand_path("../.rubocop.yml", __dir__))
+
+load Gem.bin_path("rubocop", "rubocop")
diff --git a/config/importmap.rb b/config/importmap.rb
index 7fdb198..7c2f1f5 100644
--- a/config/importmap.rb
+++ b/config/importmap.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 # Pin npm packages by running ./bin/importmap
 
 pin 'application'
 pin 'moment' # @2.30.1
-pin "js-datepicker" # @5.18.3
+pin 'js-datepicker' # @5.18.3
diff --git a/config/initializers/new_framework_defaults_8_1.rb b/config/initializers/new_framework_defaults_8_1.rb
new file mode 100644
index 0000000..8f20895
--- /dev/null
+++ b/config/initializers/new_framework_defaults_8_1.rb
@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+# Be sure to restart your server when you modify this file.
+#
+# This file eases your Rails 8.1 framework defaults upgrade.
+#
+# Uncomment each configuration one by one to switch to the new default.
+# Once your application is ready to run with all new defaults, you can remove
+# this file and set the `config.load_defaults` to `8.1`.
+#
+# Read the Guide for Upgrading Ruby on Rails for more info on each option.
+# https://guides.rubyonrails.org/upgrading_ruby_on_rails.html
+
+###
+# Skips escaping HTML entities and line separators. When set to `false`, the
+# JSON renderer no longer escapes these to improve performance.
+#
+# Example:
+#   class PostsController < ApplicationController
+#     def index
+#       render json: { key: "\u2028\u2029<>&" }
+#     end
+#   end
+#
+# Renders `{"key":"\u2028\u2029\u003c\u003e\u0026"}` with the previous default, but `{"key":"

<>&"}` with the config
+# set to `false`.
+#
+# Applications that want to keep the escaping behavior can set the config to `true`.
+#++
+# Rails.configuration.action_controller.escape_json_responses = false
+
+###
+# Skips escaping LINE SEPARATOR (U+2028) and PARAGRAPH SEPARATOR (U+2029) in JSON.
+#
+# Historically these characters were not valid inside JavaScript literal strings but that changed in ECMAScript 2019.
+# As such it's no longer a concern in modern browsers: https://caniuse.com/mdn-javascript_builtins_json_json_superset.
+#++
+# Rails.configuration.active_support.escape_js_separators_in_json = false
+
+###
+# Raises an error when order dependent finder methods (e.g. `#first`, `#second`) are called without `order` values
+# on the relation, and the model does not have any order columns (`implicit_order_column`, `query_constraints`, or
+# `primary_key`) to fall back on.
+#
+# The current behavior of not raising an error has been deprecated, and this configuration option will be removed in
+# Rails 8.2.
+#++
+# Rails.configuration.active_record.raise_on_missing_required_finder_order_columns = true
+
+###
+# Controls how Rails handles path relative URL redirects.
+# When set to `:raise`, Rails will raise an `ActionController::Redirecting::UnsafeRedirectError`
+# for relative URLs without a leading slash, which can help prevent open redirect vulnerabilities.
+#
+# Example:
+#   redirect_to "example.com"     # Raises UnsafeRedirectError
+#   redirect_to "@attacker.com"   # Raises UnsafeRedirectError
+#   redirect_to "/safe/path"      # Works correctly
+#
+# Applications that want to allow these redirects can set the config to `:log` (previous default)
+# to only log warnings, or `:notify` to send ActiveSupport notifications.
+#++
+# Rails.configuration.action_controller.action_on_path_relative_redirect = :raise
+
+###
+# Use a Ruby parser to track dependencies between Action View templates
+#++
+# Rails.configuration.action_view.render_tracker = :ruby
+
+###
+# When enabled, hidden inputs generated by `form_tag`, `token_tag`, `method_tag`, and the hidden parameter fields
+# included in `button_to` forms will omit the `autocomplete="off"` attribute.
+#
+# Applications that want to keep generating the `autocomplete` attribute for those tags can set it to `false`.
+#++
+# Rails.configuration.action_view.remove_hidden_field_autocomplete = true
diff --git a/spec/fields/acts_as_taggable_field_spec.rb b/spec/fields/acts_as_taggable_field_spec.rb
index 7abbc56..d82b9bd 100644
--- a/spec/fields/acts_as_taggable_field_spec.rb
+++ b/spec/fields/acts_as_taggable_field_spec.rb
@@ -22,6 +22,24 @@
       field = described_class.new(:tags, %w[a b], nil)
       expect(field.tags).to eq(%w[a b])
     end
+
+    it 'fetches real Tag records from the resource when constructed the way Administrate ' \
+       'actually builds fields (data: nil, resource: given), not tag_list name strings' do
+      # Administrate::Field::Base#read_value calls `resource.try(attribute)` when data is
+      # nil - and that `attribute` call is polymorphic, landing on this class's own
+      # #attribute override (returns "tag_list") rather than the raw :tags attribute this
+      # field was constructed with. A prior version of #read_value used that overridden
+      # #attribute directly, so this fetched mention.tag_list (tag-name strings) instead of
+      # mention.tags (real Tag records), and _show.html.erb's `tag.name` raised
+      # NoMethodError on a String. Only reproducible by exercising the real construction
+      # path (data: nil) - constructing with data already populated skips read_value
+      # entirely, which is why this went undetected until manual browser verification.
+      mention = create(:mention, tag_list: 'battle, correspondence')
+      field = described_class.new(:tags, nil, nil, resource: mention)
+
+      expect(field.tags).to all(be_a(ActsAsTaggableOn::Tag))
+      expect(field.tags.map(&:name)).to contain_exactly('battle', 'correspondence')
+    end
   end
 
   describe '#delimited' do
diff --git a/spec/jobs/load_big_sam_job_spec.rb b/spec/jobs/load_big_sam_job_spec.rb
index 4271655..aaf26b0 100644
--- a/spec/jobs/load_big_sam_job_spec.rb
+++ b/spec/jobs/load_big_sam_job_spec.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 require 'fileutils'
 
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index a9bc56b..4c3b332 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -49,7 +49,7 @@
   # ActiveStorage::Current is a CurrentAttributes subclass — its values are
   # reset by ActiveSupport::Executor after each inline job. Setting url_options
   # in before(:each) ensures it's present whenever a spec calls .url.
-  config.before { ActiveStorage::Current.url_options = { host: ENV['RAILS_HOST'] } }
+  config.before { ActiveStorage::Current.url_options = { host: ENV.fetch('RAILS_HOST', nil) } }
 
   # Remove this line if you're not using ActiveRecord or ActiveRecord fixtures
   config.fixture_paths = [Rails.root.join('spec', 'fixtures'), Rails.root.join('spec', 'fixtures', 'files')]
diff --git a/spec/requests/admin/mentions_spec.rb b/spec/requests/admin/mentions_spec.rb
index bc9506c..10363c3 100644
--- a/spec/requests/admin/mentions_spec.rb
+++ b/spec/requests/admin/mentions_spec.rb
@@ -14,6 +14,16 @@
       get admin_mentions_path, headers: admin_auth_headers
       expect(response).to have_http_status(:ok)
     end
+
+    # Regression test: ActsAsTaggableField's #tags previously blew up on a real tagged
+    # mention outside of a bare smoke test, since the untagged factory default never
+    # exercised the field's actual data-fetching path (see acts_as_taggable_field_spec.rb).
+    it 'renders the tags of a tagged mention' do
+      create(:mention, tag_list: 'battle, correspondence')
+      get admin_mentions_path, headers: admin_auth_headers
+      expect(response).to have_http_status(:ok)
+      expect(response.body).to include('battle').and include('correspondence')
+    end
   end
 
   describe 'GET show' do
@@ -22,6 +32,13 @@
       get admin_mention_path(mention), headers: admin_auth_headers
       expect(response).to have_http_status(:ok)
     end
+
+    it 'renders the tags of a tagged mention' do
+      mention = create(:mention, tag_list: 'battle, correspondence')
+      get admin_mention_path(mention), headers: admin_auth_headers
+      expect(response).to have_http_status(:ok)
+      expect(response.body).to include('battle').and include('correspondence')
+    end
   end
 
   describe 'GET new' do
@@ -37,5 +54,12 @@
       get edit_admin_mention_path(mention), headers: admin_auth_headers
       expect(response).to have_http_status(:ok)
     end
+
+    it 'pre-populates the tag list input of a tagged mention' do
+      mention = create(:mention, tag_list: 'battle, correspondence')
+      get edit_admin_mention_path(mention), headers: admin_auth_headers
+      expect(response).to have_http_status(:ok)
+      expect(response.body).to include('value="battle, correspondence"')
+    end
   end
 end