Reject semantic-shaped ids in HashSeparator#applicable?

The matcher regex now accepts both numeric and semantic identifier shapes
(`\d+|PROJ-\d+`) on a single alternation branch shared by the bare WP
handler and the prefixed-resource handler. Without this guard,
`version#PROJ-1` reaches HashSeparator with `oid = "PROJ-1".to_i = 0`,
which is `present?`, so it issues `Version.find_by(id: 0)` — a guaranteed
miss against the wrong table. The same shape applies to every prefix
HashSeparator handles (document, message, meeting, project, user, group,
view), turning a single pasted comment into one wasted SELECT per prefix.

Gating `applicable?` on `numeric_id?(matcher.identifier)` short-circuits
the handler before any DB lookup; the regex still matches and the text
falls through to literal output. Regression test asserts zero
`FROM "versions"` SELECTs for `version#PROJ-1`.

lib/open_project/text_formatting/matchers/link_handlers/hash_separator.rb

@@ -39,8 +39,11 @@ module OpenProject::TextFormatting::Matchers
       # Hash-separated object links
       # Condition: Separator is '#'
       # Condition: Prefix is present, checked to be one of the allowed values
+      # Condition: Identifier is numeric — prefixed resources address rows by
+      # primary key, so a semantic-shaped identifier (PROJ-1) would `to_i` to 0
+      # and run a guaranteed-miss `find_by(id: 0)`.
       def applicable?
-        matcher.sep == "#" && valid_prefix? && oid.present?
+        matcher.sep == "#" && valid_prefix? && WorkPackage::SemanticIdentifier.numeric_id?(matcher.identifier)
       end
 
       # Examples:

spec/lib/open_project/text_formatting/matchers/link_handlers/work_packages_spec.rb

@@ -270,4 +270,31 @@ RSpec.describe OpenProject::TextFormatting::Matchers::LinkHandlers::WorkPackages
                             "classic mode added unexpected WP SELECTs for semantic input:\n#{wp_selects.join("\n")}"
     end
   end
+
+  describe "prefixed resource refs with semantic-shaped identifiers",
+           with_flag: { semantic_work_package_ids: true },
+           with_settings: { work_packages_identifier: "semantic" } do
+    # `version#PROJ-1`, `message#PROJ-1`, etc. share the regex with the WP
+    # macro because `\d+|PROJ-\d+` is a single alternation. The prefixed
+    # branches address tables keyed by numeric primary key, so a semantic
+    # identifier paired with a prefix must short-circuit before the handler
+    # would otherwise issue `find_by(id: 0)` (the round-trip of any
+    # non-numeric string through `to_i`).
+    include_context "with author signed in"
+    let(:project) { create(:project, identifier: "MACROPROJ") }
+
+    it "does not query the prefixed resource table for `version#PROJ-1`" do
+      project
+      author
+
+      rendered = nil
+      recorder = ActiveRecord::QueryRecorder.new { rendered = format_text("see version#PROJ-1 here") }
+      version_selects = recorder.log.grep(/FROM "versions"/i)
+
+      expect(version_selects).to be_empty,
+                                 "expected zero versions SELECTs for semantic-shaped input, got:\n" \
+                                 "#{version_selects.join("\n")}"
+      expect(rendered).to include("version#PROJ-1")
+    end
+  end
 end