refactor: move forge ref detection from parse.body() to diff

Problem: `parse.body()` stripped forge tokens from the description,
losing the raw text. This made inline overlay rendering impossible
since the token no longer existed in the buffer.

Solution: remove the `forge.parse_ref()` branch from `parse.body()`
and call `forge.find_refs()` in `diff.parse_buffer()` instead. The
description now retains forge tokens verbatim; `_extra._forge_ref`
is still populated from the first matched ref.

lua/pending/diff.lua

@@ -1,4 +1,5 @@
 local config = require('pending.config')
+local forge = require('pending.forge')
 local parse = require('pending.parse')
 
 ---@class pending.ParsedEntry
@@ -56,6 +57,8 @@ function M.parse_buffer(lines)
       end
       local description, metadata = parse.body(stripped)
       if description and description ~= '' then
+        local refs = forge.find_refs(description)
+        local forge_ref = refs[1] and refs[1].ref or nil
         table.insert(result, {
           type = 'task',
           id = id and tonumber(id) or nil,
@@ -66,7 +69,7 @@ function M.parse_buffer(lines)
           due = metadata.due,
           rec = metadata.rec,
           rec_mode = metadata.rec_mode,
-          forge_ref = metadata.forge_ref,
+          forge_ref = forge_ref,
           lnum = i,
         })
       end

lua/pending/parse.lua

@@ -6,7 +6,6 @@ local config = require('pending.config')
 ---@field rec? string
 ---@field rec_mode? 'scheduled'|'completion'
 ---@field priority? integer
----@field forge_ref? pending.ForgeRef
 
 ---@class pending.parse
 local M = {}
@@ -597,17 +596,7 @@ function M.body(text)
               metadata.rec = raw_spec
               i = i - 1
             else
-              local forge = require('pending.forge')
-              local ref = forge.parse_ref(token)
-              if ref then
-                if metadata.forge_ref then
-                  break
-                end
-                metadata.forge_ref = ref
-                i = i - 1
-              else
-                break
-              end
+              break
             end
           end
         end