merge: resolve v1.21.1 conflicts with custom

Resolve all 10 upstream v1.21.1 merge conflicts into custom, keeping
custom's GitLab/Gitea forge customizations layered on upstream while
lifting upstream improvements. Restored tr.ts i18n key parity with the
custom en.ts dictionary (471 custom forge keys added, en fallback) so the
upstream-introduced locale stays in parity.

Also stage bun.lock version alignment (1.21.0 -> 1.21.1) that matches the
staged package.json bump.

Verification: ui + web type-check pass; ui/web tests pass except
pre-existing failures on the custom baseline (forge.test.ts, session-actions,
issue-1637-2270, routes.test.js fs-stat directory scope).

bun.lock

@@ -97,7 +97,7 @@
     },
     "packages/electron": {
       "name": "@openchamber/electron",
-      "version": "1.21.0",
+      "version": "1.21.1",
       "dependencies": {
         "@openchamber/web": "workspace:*",
         "electron-context-menu": "^4.1.2",
@@ -134,7 +134,7 @@
     },
     "packages/ui": {
       "name": "@openchamber/ui",
-      "version": "1.21.0",
+      "version": "1.21.1",
       "dependencies": {
         "@aparajita/capacitor-secure-storage": "^8.0.0",
         "@base-ui/react": "^1.4.0",
@@ -241,7 +241,7 @@
     },
     "packages/vscode": {
       "name": "openchamber",
-      "version": "1.21.0",
+      "version": "1.21.1",
       "dependencies": {
         "@openchamber/ui": "workspace:*",
         "@opencode-ai/sdk": "1.18.25",
@@ -264,7 +264,7 @@
     },
     "packages/web": {
       "name": "@openchamber/web",
-      "version": "1.21.0",
+      "version": "1.21.1",
       "bin": {
         "openchamber": "./bin/cli.js",
       },