diff --git a/.github/ISSUE_TEMPLATE/bug_report.yml b/.github/ISSUE_TEMPLATE/bug_report.yml
new file mode 100644
index 0000000..371051d
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/bug_report.yml
@@ -0,0 +1,77 @@
+name: Bug Report
+description: Report a bug
+title: "bug: "
+labels: [bug]
+body:
+  - type: checkboxes
+    attributes:
+      label: Prerequisites
+      options:
+        - label: I have searched [existing issues](https://github.com/barrettruth/fugitive-ts.nvim/issues)
+          required: true
+        - label: I have updated to the latest version
+          required: true
+
+  - type: textarea
+    attributes:
+      label: "Neovim version"
+      description: "Output of `nvim --version`"
+      render: text
+    validations:
+      required: true
+
+  - type: input
+    attributes:
+      label: "Operating system"
+      placeholder: "e.g. Arch Linux, macOS 15, Ubuntu 24.04"
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Description
+      description: What happened? What did you expect?
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Steps to reproduce
+      description: Minimal steps to trigger the bug
+      value: |
+        1.
+        2.
+        3.
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: "Health check"
+      description: "Output of `:checkhealth fugitive-ts`"
+      render: text
+
+  - type: textarea
+    attributes:
+      label: Minimal reproduction
+      description: |
+        Save the script below as `repro.lua`, edit if needed, and run:
+        ```
+        nvim -u repro.lua
+        ```
+        Confirm the bug reproduces with this config before submitting.
+      render: lua
+      value: |
+        vim.env.LAZY_STDPATH = '.repro'
+        load(vim.fn.system('curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua'))()
+        require('lazy.nvim').setup({
+          spec = {
+            'tpope/vim-fugitive',
+            {
+              'barrettruth/fugitive-ts.nvim',
+              opts = {},
+            },
+          },
+        })
+    validations:
+      required: true
diff --git a/.github/ISSUE_TEMPLATE/config.yml b/.github/ISSUE_TEMPLATE/config.yml
new file mode 100644
index 0000000..017dbad
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/config.yml
@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Questions
+    url: https://github.com/barrettruth/fugitive-ts.nvim/discussions
+    about: Ask questions and discuss ideas
diff --git a/.github/ISSUE_TEMPLATE/feature_request.yml b/.github/ISSUE_TEMPLATE/feature_request.yml
new file mode 100644
index 0000000..e85ddba
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/feature_request.yml
@@ -0,0 +1,28 @@
+name: Feature Request
+description: Suggest a feature
+title: "feat: "
+labels: [enhancement]
+body:
+  - type: checkboxes
+    attributes:
+      label: Prerequisites
+      options:
+        - label: I have searched [existing issues](https://github.com/barrettruth/fugitive-ts.nvim/issues)
+          required: true
+
+  - type: textarea
+    attributes:
+      label: Problem
+      description: What problem does this solve?
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Proposed solution
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Alternatives considered
diff --git a/lua/fugitive-ts/highlight.lua b/lua/fugitive-ts/highlight.lua
index 122bb6d..26b2548 100644
--- a/lua/fugitive-ts/highlight.lua
+++ b/lua/fugitive-ts/highlight.lua
@@ -1,21 +1,6 @@
 local M = {}
 
-local debug_enabled = false
-
----@param enabled boolean
-function M.set_debug(enabled)
-  debug_enabled = enabled
-end
-
----@param msg string
----@param ... any
-local function dbg(msg, ...)
-  if not debug_enabled then
-    return
-  end
-  local formatted = string.format(msg, ...)
-  vim.notify('[fugitive-ts] ' .. formatted, vim.log.levels.DEBUG)
-end
+local dbg = require('fugitive-ts.log').dbg
 
 ---@param bufnr integer
 ---@param ns integer
diff --git a/lua/fugitive-ts/init.lua b/lua/fugitive-ts/init.lua
index f7f46c9..c5087d0 100644
--- a/lua/fugitive-ts/init.lua
+++ b/lua/fugitive-ts/init.lua
@@ -30,6 +30,7 @@
 local M = {}
 
 local highlight = require('fugitive-ts.highlight')
+local log = require('fugitive-ts.log')
 local parser = require('fugitive-ts.parser')
 
 local ns = vim.api.nvim_create_namespace('fugitive_ts')
@@ -104,15 +105,7 @@ function M.is_fugitive_buffer(bufnr)
   return vim.api.nvim_buf_get_name(bufnr):match('^fugitive://') ~= nil
 end
 
----@param msg string
----@param ... any
-local function dbg(msg, ...)
-  if not config.debug then
-    return
-  end
-  local formatted = string.format(msg, ...)
-  vim.notify('[fugitive-ts] ' .. formatted, vim.log.levels.DEBUG)
-end
+local dbg = log.dbg
 
 ---@param bufnr integer
 local function highlight_buffer(bufnr)
@@ -338,9 +331,18 @@ function M.setup(opts)
     })
   end
 
+  if opts.debounce_ms and opts.debounce_ms < 0 then
+    error('fugitive-ts: debounce_ms must be >= 0')
+  end
+  if opts.treesitter and opts.treesitter.max_lines and opts.treesitter.max_lines < 1 then
+    error('fugitive-ts: treesitter.max_lines must be >= 1')
+  end
+  if opts.vim and opts.vim.max_lines and opts.vim.max_lines < 1 then
+    error('fugitive-ts: vim.max_lines must be >= 1')
+  end
+
   config = vim.tbl_deep_extend('force', default_config, opts)
-  parser.set_debug(config.debug)
-  highlight.set_debug(config.debug)
+  log.set_enabled(config.debug)
 
   compute_highlight_groups()
 
diff --git a/lua/fugitive-ts/log.lua b/lua/fugitive-ts/log.lua
new file mode 100644
index 0000000..be43978
--- /dev/null
+++ b/lua/fugitive-ts/log.lua
@@ -0,0 +1,19 @@
+local M = {}
+
+local enabled = false
+
+---@param val boolean
+function M.set_enabled(val)
+  enabled = val
+end
+
+---@param msg string
+---@param ... any
+function M.dbg(msg, ...)
+  if not enabled then
+    return
+  end
+  vim.notify('[fugitive-ts] ' .. string.format(msg, ...), vim.log.levels.DEBUG)
+end
+
+return M
diff --git a/lua/fugitive-ts/parser.lua b/lua/fugitive-ts/parser.lua
index e5b720e..ab6daed 100644
--- a/lua/fugitive-ts/parser.lua
+++ b/lua/fugitive-ts/parser.lua
@@ -9,22 +9,7 @@
 
 local M = {}
 
-local debug_enabled = false
-
----@param enabled boolean
-function M.set_debug(enabled)
-  debug_enabled = enabled
-end
-
----@param msg string
----@param ... any
-local function dbg(msg, ...)
-  if not debug_enabled then
-    return
-  end
-  local formatted = string.format(msg, ...)
-  vim.notify('[fugitive-ts] ' .. formatted, vim.log.levels.DEBUG)
-end
+local dbg = require('fugitive-ts.log').dbg
 
 ---@param filename string
 ---@return string?
@@ -116,7 +101,13 @@ function M.parse_buffer(bufnr)
       local prefix = line:sub(1, 1)
       if prefix == ' ' or prefix == '+' or prefix == '-' then
         table.insert(hunk_lines, line)
-      elseif line == '' or line:match('^[MADRC%?!]%s+') or line:match('^%a') then
+      elseif
+        line == ''
+        or line:match('^[MADRC%?!]%s+')
+        or line:match('^diff ')
+        or line:match('^index ')
+        or line:match('^Binary ')
+      then
         flush_hunk()
         current_filename = nil
         current_ft = nil