Fix build errors and add complete dialyzer specs

- Remove erlc_paths and erlc_include_path from mix.exs (leftover from Gleam)
- Add comprehensive dialyzer specs to Encoding module
- Add missing dialyzer specs to EncodingUtils module
- Ensure all public and private functions have proper type specifications

This fixes the Docker build error about undefined erlc_paths function
and ensures full dialyzer compliance.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

lib/aprsme/encoding.ex

@@ -9,17 +9,20 @@ defmodule Aprsme.Encoding do
   Sanitizes a binary to ensure it can be safely JSON encoded.
   Handles latin1 conversion and removes control characters.
   """
+  @spec sanitize_string(binary()) :: binary()
   def sanitize_string(input) when is_binary(input) do
     input
     |> try_utf8_conversion()
     |> clean_control_characters()
   end
 
+  @spec sanitize_string(any()) :: binary()
   def sanitize_string(_), do: ""
 
   @doc """
   Type-safe float conversion with validation
   """
+  @spec to_float_safe(binary()) :: {:ok, float()} | nil
   def to_float_safe(value) when is_binary(value) do
     sanitized = value
                 |> String.trim()
@@ -33,20 +36,24 @@ defmodule Aprsme.Encoding do
     end
   end
 
+  @spec to_float_safe(any()) :: nil
   def to_float_safe(_), do: nil
 
   @doc """
   Convert binary to hex string
   """
+  @spec to_hex(binary()) :: binary()
   def to_hex(input) when is_binary(input) do
     Base.encode16(input)
   end
 
+  @spec to_hex(any()) :: binary()
   def to_hex(_), do: ""
 
   @doc """
   Check if a value looks like it has weather data
   """
+  @spec has_weather_data(any(), any(), any(), any()) :: boolean()
   def has_weather_data(temperature, humidity, wind_speed, pressure) do
     not is_nil(temperature) or
     not is_nil(humidity) or
@@ -57,6 +64,12 @@ defmodule Aprsme.Encoding do
   @doc """
   Get encoding information about a binary
   """
+  @spec encoding_info(binary()) :: %{
+    valid_utf8: boolean(),
+    byte_count: non_neg_integer(),
+    char_count: non_neg_integer() | nil,
+    invalid_at: non_neg_integer() | nil
+  }
   def encoding_info(input) when is_binary(input) do
     byte_count = byte_size(input)
     
@@ -79,6 +92,12 @@ defmodule Aprsme.Encoding do
     end
   end
 
+  @spec encoding_info(any()) :: %{
+    valid_utf8: boolean(),
+    byte_count: non_neg_integer(),
+    char_count: nil,
+    invalid_at: nil
+  }
   def encoding_info(_) do
     %{
       valid_utf8: false,
@@ -90,6 +109,7 @@ defmodule Aprsme.Encoding do
 
   # Private functions
 
+  @spec try_utf8_conversion(binary()) :: binary()
   defp try_utf8_conversion(input) do
     if String.valid?(input) do
       input
@@ -99,6 +119,7 @@ defmodule Aprsme.Encoding do
     end
   end
 
+  @spec latin1_to_utf8(binary()) :: binary()
   defp latin1_to_utf8(input) do
     try do
       input
@@ -110,6 +131,7 @@ defmodule Aprsme.Encoding do
     end
   end
 
+  @spec latin1_char_to_utf8(0..255) :: binary()
   defp latin1_char_to_utf8(byte) when byte <= 127 do
     <<byte>>
   end
@@ -120,6 +142,7 @@ defmodule Aprsme.Encoding do
     <<0xC0 + div(byte, 64), 0x80 + rem(byte, 64)>>
   end
 
+  @spec clean_control_characters(binary()) :: binary()
   defp clean_control_characters(s) do
     s
     |> String.graphemes()
@@ -128,6 +151,7 @@ defmodule Aprsme.Encoding do
     |> String.trim()
   end
 
+  @spec valid_grapheme?(String.grapheme()) :: boolean()
   defp valid_grapheme?(grapheme) do
     case String.to_charlist(grapheme) do
       [cp] ->
@@ -148,6 +172,7 @@ defmodule Aprsme.Encoding do
     end
   end
 
+  @spec find_invalid_byte_position(binary()) :: non_neg_integer() | nil
   defp find_invalid_byte_position(input) do
     input
     |> :binary.bin_to_list()
@@ -159,6 +184,7 @@ defmodule Aprsme.Encoding do
     end)
   end
 
+  @spec valid_utf8_continuation?(binary(), non_neg_integer()) :: boolean()
   defp valid_utf8_continuation?(binary, pos) do
     try do
       <<_::binary-size(pos), char::utf8, _::binary>> = binary

lib/aprsme/encoding_utils.ex

@@ -76,6 +76,7 @@ defmodule Aprsme.EncodingUtils do
   def to_float(_), do: nil
 
   # Helper to check if a float is finite (not infinity or NaN)
+  @spec finite_float?(any()) :: boolean()
   defp finite_float?(float) when is_float(float) do
     # In Elixir, we can't have infinity or NaN in regular floats
     # This function is kept for defensive programming
@@ -319,6 +320,7 @@ defmodule Aprsme.EncodingUtils do
 
   def sanitize_data_extended(data_extended), do: data_extended
 
+  @spec sanitize_map_value(any()) :: any()
   defp sanitize_map_value(val) when is_binary(val), do: sanitize_string(val)
   defp sanitize_map_value(val), do: val
 

mix.exs

@@ -9,8 +9,6 @@ defmodule Aprsme.MixProject do
       archives: [],
       compilers: Mix.compilers(),
       elixirc_paths: elixirc_paths(Mix.env()),
-      erlc_paths: erlc_paths(Mix.env()),
-      erlc_include_path: "build/#{Mix.env()}/erlang/aprsme/include",
       start_permanent: Mix.env() == :prod,
       aliases: aliases(),
       deps: deps(),