✨ Improved support for Merge Recipes

### Added

- **`Recipe::Runner` target file override**: Accept `target_files` parameter to override recipe targets
  - `Runner.new(recipe, target_files: ["file1.md", "file2.md"])` - Process only specified files
  - Paths are expanded relative to `base_dir`
  - When not specified, falls back to recipe's configured targets
- **`exe/ast-merge-recipe` file arguments**: Accept target files on command line
  - `ast-merge-recipe recipe.yml file1.md file2.md` - Override recipe targets
  - Updated help text and banner to document new usage
- **`bin/update_gem_family_section` file arguments**: Accept target files on command line
  - `bin/update_gem_family_section vendor/my-gem/README.md` - Process specific file(s)
  - If no files specified, defaults to `README.md` + `vendor/*/README.md`
  - Added `--skip-fix` option to skip the formatting fix step

### Changed

- **`bin/update_gem_family_section`**: Refactored to use `OptionParser` for clean option handling
  - Consistent with `bin/fix_readme_formatting` style
  - Properly separates options from file arguments

Author: pboling

CHANGELOG.md

@@ -20,8 +20,24 @@ Please file a bug if you notice a violation of semantic versioning.
 
 ### Added
 
+- **`Recipe::Runner` target file override**: Accept `target_files` parameter to override recipe targets
+  - `Runner.new(recipe, target_files: ["file1.md", "file2.md"])` - Process only specified files
+  - Paths are expanded relative to `base_dir`
+  - When not specified, falls back to recipe's configured targets
+- **`exe/ast-merge-recipe` file arguments**: Accept target files on command line
+  - `ast-merge-recipe recipe.yml file1.md file2.md` - Override recipe targets
+  - Updated help text and banner to document new usage
+- **`bin/update_gem_family_section` file arguments**: Accept target files on command line
+  - `bin/update_gem_family_section vendor/my-gem/README.md` - Process specific file(s)
+  - If no files specified, defaults to `README.md` + `vendor/*/README.md`
+  - Added `--skip-fix` option to skip the formatting fix step
+
 ### Changed
 
+- **`bin/update_gem_family_section`**: Refactored to use `OptionParser` for clean option handling
+  - Consistent with `bin/fix_readme_formatting` style
+  - Properly separates options from file arguments
+
 ### Deprecated
 
 ### Removed

Gemfile.lock

@@ -1,20 +1,3 @@
-GIT
-  remote: https://github.com/pboling/ruby-tree-sitter.git
-  revision: c36cff9cbf55ca1512cc49d8739e4efc2ff0a962
-  branch: tree_haver
-  specs:
-    ruby_tree_sitter (2.0.0)
-      oppen (~> 1.0)
-      sorbet-runtime
-      zeitwerk
-
-GIT
-  remote: https://github.com/pboling/tree_stump.git
-  revision: 117b262335214bbfb3ec8210dc0efe336db03538
-  branch: tree_haver
-  specs:
-    tree_stump (0.1.0)
-
 GIT
   remote: https://github.com/pboling/yard-junk.git
   revision: 54ccebabbfa9a9cd44d0b991687ebbfd22c32b55
@@ -27,6 +10,145 @@ GIT
       rainbow
       yard
 
+PATH
+  remote: vendor/bash-merge
+  specs:
+    bash-merge (2.0.3)
+      ast-merge (~> 4.0, >= 4.0.1)
+      tree_haver (~> 5.0, >= 5.0.1)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/commonmarker-merge
+  specs:
+    commonmarker-merge (1.0.0)
+      commonmarker (~> 2.0)
+      markdown-merge (~> 1.0)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/dotenv-merge
+  specs:
+    dotenv-merge (1.0.1)
+      ast-merge (~> 4.0, >= 4.0.0)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/json-merge
+  specs:
+    json-merge (1.1.0)
+      ast-merge (~> 4.0, >= 4.0.0)
+      tree_haver (~> 5.0, >= 5.0.0)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/jsonc-merge
+  specs:
+    jsonc-merge (1.0.0)
+      ast-merge (~> 4.0, >= 4.0.0)
+      tree_haver (~> 5.0, >= 5.0.0)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/kettle-dev
+  specs:
+    kettle-dev (1.2.5)
+
+PATH
+  remote: vendor/kettle-soup-cover
+  specs:
+    kettle-soup-cover (1.1.1)
+      simplecov (~> 0.22)
+      simplecov-cobertura (~> 3.0)
+      simplecov-console (~> 0.9, >= 0.9.3)
+      simplecov-html (~> 0.13, >= 0.13.1)
+      simplecov-lcov (~> 0.8)
+      simplecov-rcov (~> 0.3, >= 0.3.7)
+      simplecov_json_formatter (~> 0.1, >= 0.1.4)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/kettle-test
+  specs:
+    kettle-test (1.0.7)
+      appraisal2 (~> 3.0)
+      backports (~> 3.0)
+      rspec (~> 3.0)
+      rspec-block_is_expected (~> 1.0, >= 1.0.6)
+      rspec-pending_for (~> 0.1, >= 0.1.19)
+      rspec-stubbed_env (~> 1.0, >= 1.0.4)
+      rspec_junit_formatter (~> 0.6)
+      silent_stream (~> 1.0, >= 1.0.12)
+      timecop-rspec (~> 1.0, >= 1.0.3)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/markdown-merge
+  specs:
+    markdown-merge (1.0.0)
+      ast-merge (~> 4.0, >= 4.0.0)
+      parslet (~> 2.0)
+      tree_haver (~> 5.0, >= 5.0.0)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/markly-merge
+  specs:
+    markly-merge (1.0.0)
+      markdown-merge (~> 1.0)
+      markly (~> 0.15)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/prism-merge
+  specs:
+    prism-merge (2.0.0)
+      ast-merge (~> 4.0, >= 4.0.0)
+      prism (~> 1.6)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/psych-merge
+  specs:
+    psych-merge (1.0.0)
+      ast-merge (~> 4.0, >= 4.0.0)
+      psych (~> 5.0)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/rbs-merge
+  specs:
+    rbs-merge (1.0.0)
+      ast-merge (~> 4.0, >= 4.0.0)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/ruby-tree-sitter
+  specs:
+    ruby_tree_sitter (2.0.0)
+      oppen (~> 1.0)
+      sorbet-runtime
+      zeitwerk
+
+PATH
+  remote: vendor/toml-merge
+  specs:
+    toml-merge (2.0.0)
+      ast-merge (~> 4.0, >= 4.0.0)
+      tree_haver (~> 5.0, >= 5.0.0)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/tree_haver
+  specs:
+    tree_haver (5.0.1)
+      version_gem (~> 1.1, >= 1.1.9)
+
+PATH
+  remote: vendor/tree_stump
+  specs:
+    tree_stump (0.1.0)
+
 PATH
   remote: .
   specs:
@@ -107,27 +229,6 @@ GEM
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
     json (2.18.0)
-    kettle-dev (1.2.4)
-    kettle-soup-cover (1.1.1)
-      simplecov (~> 0.22)
-      simplecov-cobertura (~> 3.0)
-      simplecov-console (~> 0.9, >= 0.9.3)
-      simplecov-html (~> 0.13, >= 0.13.1)
-      simplecov-lcov (~> 0.8)
-      simplecov-rcov (~> 0.3, >= 0.3.7)
-      simplecov_json_formatter (~> 0.1, >= 0.1.4)
-      version_gem (~> 1.1, >= 1.1.9)
-    kettle-test (1.0.7)
-      appraisal2 (~> 3.0)
-      backports (~> 3.0)
-      rspec (~> 3.0)
-      rspec-block_is_expected (~> 1.0, >= 1.0.6)
-      rspec-pending_for (~> 0.1, >= 0.1.19)
-      rspec-stubbed_env (~> 1.0, >= 1.0.4)
-      rspec_junit_formatter (~> 0.6)
-      silent_stream (~> 1.0, >= 1.0.12)
-      timecop-rspec (~> 1.0, >= 1.0.3)
-      version_gem (~> 1.1, >= 1.1.9)
     kramdown (2.5.1)
       rexml (>= 3.3.9)
     kramdown-parser-gfm (1.1.0)
@@ -322,8 +423,6 @@ GEM
     toml-rb (4.1.0)
       citrus (~> 3.0, > 3.0)
       racc (~> 1.7)
-    tree_haver (5.0.1)
-      version_gem (~> 1.1, >= 1.1.9)
     tsort (0.2.0)
     ttfunk (1.8.0)
       bigdecimal (~> 3.1)
@@ -362,28 +461,38 @@ DEPENDENCIES
   addressable (>= 2.8, < 3)
   appraisal2 (~> 3.0)
   ast-merge!
+  bash-merge!
   benchmark (~> 0.5, >= 0.5.0)
   bundler-audit (~> 0.9.2)
   citrus
   commonmarker
+  commonmarker-merge!
   debug (>= 1.1)
+  dotenv-merge!
   erb (~> 5.0)
   ffi
   gem_bench (~> 2.0, >= 2.0.5)
   gitmoji-regex (~> 1.0, >= 1.0.3)
   irb (~> 1.16)
-  kettle-dev (~> 1.1)
-  kettle-soup-cover (~> 1.1, ~> 1.0, >= 1.1.1, >= 1.0.10)
-  kettle-test (~> 1.0, >= 1.0.7)
+  json-merge!
+  jsonc-merge!
+  kettle-dev (~> 1.1, >= 0)!
+  kettle-soup-cover (~> 1.1, >= 1.1.1, >= 0)!
+  kettle-test (~> 1.0, >= 1.0.7, >= 0)!
   kramdown (~> 2.5, >= 2.5.1)
   kramdown-parser-gfm (~> 1.1)
+  markdown-merge!
   markly (~> 0.15, >= 0.15.2)
+  markly-merge!
   mutex_m (~> 0.2)
   ostruct (~> 0.6, >= 0.6.3)
   parslet
   prism (~> 1.6)
+  prism-merge!
+  psych-merge!
   rake (~> 13.0)
   rbs (>= 3.10)
+  rbs-merge!
   rdoc (~> 6.11)
   reek (~> 6.5)
   require_bench (~> 1.0, >= 1.0.4)
@@ -398,7 +507,9 @@ DEPENDENCIES
   stone_checksums (~> 1.0, >= 1.0.2)
   stringio (>= 3.0)
   toml
+  toml-merge!
   toml-rb
+  tree_haver!
   tree_stump!
   unparser (~> 0.8, >= 0.8.1)
   yaml-converter (~> 0.1)
@@ -415,19 +526,22 @@ CHECKSUMS
   ast (2.4.3) sha256=954615157c1d6a382bc27d690d973195e79db7f55e9765ac7c481c60bdb4d383
   ast-merge (4.0.1)
   backports (3.25.3) sha256=94298d32dc3c40ca15633b54e282780b49e2db0c045f602ea1907e4f63a17235
+  bash-merge (2.0.3)
   benchmark (0.5.0) sha256=465df122341aedcb81a2a24b4d3bd19b6c67c1530713fd533f3ff034e419236c
   bigdecimal (3.3.1) sha256=eaa01e228be54c4f9f53bf3cc34fe3d5e845c31963e7fcc5bedb05a4e7d52218
   bundler-audit (0.9.3) sha256=81c8766c71e47d0d28a0f98c7eed028539f21a6ea3cd8f685eb6f42333c9b4e9
   citrus (3.0.2) sha256=4ec2412fc389ad186735f4baee1460f7900a8e130ffe3f216b30d4f9c684f650
   commonmarker (2.6.1-arm-linux) sha256=ee064b7c5d446d841299a0f9a38d7e6d486c44c89b4237695c7d59d8cf256ddb
   commonmarker (2.6.1-x86_64-linux) sha256=7f43729af032cfb88c0e897f53bf37ad78c6ec28220a0911f5e34b4f041e7ec7
+  commonmarker-merge (1.0.0)
   concurrent-ruby (1.3.6) sha256=6b56837e1e7e5292f9864f34b69c5a2cbc75c0cf5338f1ce9903d10fa762d5ab
   date (3.5.1) sha256=750d06384d7b9c15d562c76291407d89e368dda4d4fff957eb94962d325a0dc0
   debug (1.11.1) sha256=2e0b0ac6119f2207a6f8ac7d4a73ca8eb4e440f64da0a3136c30343146e952b6
   delegate (0.6.1) sha256=54cf946cacfe05b1c23114edd8fbd8d54e9cea7abf36b95130ab53cc88b8f7e4
   diff-lcs (1.6.2) sha256=9ae0d2cba7d4df3075fe8cd8602a8604993efc0dfa934cff568969efb1909962
   diffy (3.4.4) sha256=79384ab5ca82d0e115b2771f0961e27c164c456074bd2ec46b637ebf7b6e47e3
   docile (1.4.1) sha256=96159be799bfa73cdb721b840e9802126e4e03dfc26863db73647204c727f21e
+  dotenv-merge (1.0.1)
   dry-configurable (1.3.0) sha256=882d862858567fc1210d2549d4c090f34370fc1bb7c5c1933de3fe792e18afa8
   dry-core (1.2.0) sha256=0cc5a7da88df397f153947eeeae42e876e999c1e30900f3c536fb173854e96a1
   dry-inflector (1.3.0) sha256=441082dde958db39df7353c71e520c05732e8da9ace28c78da2d0f1d6c669fa3
@@ -444,15 +558,19 @@ CHECKSUMS
   io-console (0.8.2) sha256=d6e3ae7a7cc7574f4b8893b4fca2162e57a825b223a177b7afa236c5ef9814cc
   irb (1.16.0) sha256=2abe56c9ac947cdcb2f150572904ba798c1e93c890c256f8429981a7675b0806
   json (2.18.0) sha256=b10506aee4183f5cf49e0efc48073d7b75843ce3782c68dbeb763351c08fd505
-  kettle-dev (1.2.4) sha256=71373c67fe7eb0a9656e70dfd10cf226a15083b6d1be18dafcb5360f21ee98b6
-  kettle-soup-cover (1.1.1) sha256=2303885a9d8485d8d43cb250bcf73570f6b6fb997526beeaef3ef54e3501d445
-  kettle-test (1.0.7) sha256=16fcb8b1bc12366f443d0ec9d125c1865249865c7afff7ef856e602436d4cdc7
+  json-merge (1.1.0)
+  jsonc-merge (1.0.0)
+  kettle-dev (1.2.5)
+  kettle-soup-cover (1.1.1)
+  kettle-test (1.0.7)
   kramdown (2.5.1) sha256=87bbb6abd9d3cebe4fc1f33e367c392b4500e6f8fa19dd61c0972cf4afe7368c
   kramdown-parser-gfm (1.1.0) sha256=fb39745516427d2988543bf01fc4cf0ab1149476382393e0e9c48592f6581729
   language_server-protocol (3.17.0.5) sha256=fd1e39a51a28bf3eec959379985a72e296e9f9acfce46f6a79d31ca8760803cc
   lint_roller (1.1.0) sha256=2c0c845b632a7d172cb849cc90c1bce937a28c5c8ccccb50dfd46a485003cc87
   logger (1.7.0) sha256=196edec7cc44b66cfb40f9755ce11b392f21f7967696af15d274dde7edff0203
+  markdown-merge (1.0.0)
   markly (0.15.2) sha256=65dae965d4dd4ecd997fba43b93acc0fe7dadfec6f07a748640c7a9299a8551e
+  markly-merge (1.0.0)
   matrix (0.4.3) sha256=a0d5ab7ddcc1973ff690ab361b67f359acbb16958d1dc072b8b956a286564c5b
   mutex_m (0.3.0) sha256=cfcb04ac16b69c4813777022fdceda24e9f798e48092a2b817eb4c0a782b0751
   nokogiri (1.19.0-arm-linux-gnu) sha256=572a259026b2c8b7c161fdb6469fa2d0edd2b61cd599db4bbda93289abefbfe5
@@ -468,12 +586,15 @@ CHECKSUMS
   prawn (2.5.0) sha256=f4e20e3b4f30bf5b9ae37dad15eb421831594553aa930b2391b0fa0a99c43cb6
   prettyprint (0.2.0) sha256=2bc9e15581a94742064a3cc8b0fb9d45aae3d03a1baa6ef80922627a0766f193
   prism (1.7.0) sha256=10062f734bf7985c8424c44fac382ac04a58124ea3d220ec3ba9fe4f2da65103
+  prism-merge (2.0.0)
   psych (5.3.1) sha256=eb7a57cef10c9d70173ff74e739d843ac3b2c019a003de48447b2963d81b1974
+  psych-merge (1.0.0)
   public_suffix (7.0.2) sha256=9114090c8e4e7135c1fd0e7acfea33afaab38101884320c65aaa0ffb8e26a857
   racc (1.8.1) sha256=4a7f6929691dbec8b5209a0b373bc2614882b55fc5d2e447a21aaa691303d62f
   rainbow (3.1.1) sha256=039491aa3a89f42efa1d6dec2fc4e62ede96eb6acd95e52f1ad581182b79bc6a
   rake (13.3.1) sha256=8c9e89d09f66a26a01264e7e3480ec0607f0c497a861ef16063604b1b08eb19c
   rbs (3.10.2) sha256=bd8a5dc4c62f229f020146b61844a31f9c79e649449d212904a474eb79c846fc
+  rbs-merge (1.0.0)
   rdoc (6.17.0) sha256=0f50d4e568fc98195f9bb155a9e8dff6c7feabfb515fb22ef6df1d12ad5a02b7
   reek (6.5.0) sha256=d26d3a492773b2bbc228888067a21afe33ac07954a17dbd64cdeae42c4c69be1
   regexp_parser (2.11.3) sha256=ca13f381a173b7a93450e53459075c9b76a10433caadcb2f1180f2c741fc55a4
@@ -526,8 +647,9 @@ CHECKSUMS
   timecop (0.9.10) sha256=12ba45ce57cdcf6b1043cb6cdffa6381fd89ce10d369c28a7f6f04dc1b0cd8eb
   timecop-rspec (1.0.3) sha256=005f14841bb606dcaefb060e321b5388e2e59537742bee8b3a9a9a40e598fab9
   toml (0.3.0) sha256=0a91d0f76a9036e84e44f95693b12f58d358c1df3ac8e3b5271f2056ecc6e4b9
+  toml-merge (2.0.0)
   toml-rb (4.1.0) sha256=14456ec4549e4703881bf04b83a56f3264ef99884880092d83c98a2058d95846
-  tree_haver (5.0.1) sha256=e50041af146a400194ab3fdb62ecd9271af9c5747b71f08efeca5f1f80096751
+  tree_haver (5.0.1)
   tree_stump (0.1.0)
   tsort (0.2.0) sha256=9650a793f6859a43b6641671278f79cfead60ac714148aabe4e3f0060480089f
   ttfunk (1.8.0) sha256=a7cbc7e489cc46e979dde04d34b5b9e4f5c8f1ee5fc6b1a7be39b829919d20ca