fix(discord): land proxy/media/reaction/model-picker regressions

Reimplements core Discord fixes from #25277 #25523 #25575 #25588 #25731 with expanded tests.

- thread proxy-aware fetch into inbound attachment/sticker downloads
- fetch /gateway/bot via proxy dispatcher before ws connect
- wire statusReactions emojis/timing overrides into controller
- compact model-picker custom_id keys with backward-compatible parsing

Co-authored-by: openperf <openperf@users.noreply.github.com>
Co-authored-by: chilu18 <chilu18@users.noreply.github.com>
Co-authored-by: Yipsh <Yipsh@users.noreply.github.com>
Co-authored-by: lbo728 <lbo728@users.noreply.github.com>
Co-authored-by: s1korrrr <s1korrrr@users.noreply.github.com>

src/discord/monitor/model-picker.test.ts

@@ -117,6 +117,28 @@ describe("Discord model picker custom_id", () => {
     });
   });
 
+  it("parses compact custom_id aliases", () => {
+    const parsed = parseDiscordModelPickerData({
+      c: "models",
+      a: "submit",
+      v: "models",
+      u: "42",
+      p: "openai",
+      g: "3",
+      mi: "2",
+    });
+
+    expect(parsed).toEqual({
+      command: "models",
+      action: "submit",
+      view: "models",
+      userId: "42",
+      provider: "openai",
+      page: 3,
+      modelIndex: 2,
+    });
+  });
+
   it("parses optional submit model index", () => {
     const parsed = parseDiscordModelPickerData({
       cmd: "models",
@@ -179,6 +201,21 @@ describe("Discord model picker custom_id", () => {
       }),
     ).toThrow(/custom_id exceeds/i);
   });
+
+  it("keeps typical submit ids under Discord max length", () => {
+    const customId = buildDiscordModelPickerCustomId({
+      command: "models",
+      action: "submit",
+      view: "models",
+      provider: "azure-openai-responses",
+      page: 1,
+      providerPage: 1,
+      modelIndex: 10,
+      userId: "12345678901234567890",
+    });
+
+    expect(customId.length).toBeLessThanOrEqual(DISCORD_CUSTOM_ID_MAX_CHARS);
+  });
 });
 
 describe("provider paging", () => {
@@ -325,7 +362,7 @@ describe("Discord model picker rendering", () => {
       return parsed?.action === "provider";
     });
     expect(providerButtons).toHaveLength(Object.keys(entries).length);
-    expect(allButtons.some((component) => (component.custom_id ?? "").includes(":act=nav:"))).toBe(
+    expect(allButtons.some((component) => (component.custom_id ?? "").includes(";a=nav;"))).toBe(
       false,
     );
   });
@@ -352,7 +389,7 @@ describe("Discord model picker rendering", () => {
     expect(rows.length).toBeGreaterThan(0);
 
     const allButtons = rows.flatMap((row) => row.components ?? []);
-    expect(allButtons.some((component) => (component.custom_id ?? "").includes(":act=nav:"))).toBe(
+    expect(allButtons.some((component) => (component.custom_id ?? "").includes(";a=nav;"))).toBe(
       false,
     );
   });