fix(desktop): render rich project work item content (#3100)

## Summary

Project issues, pull requests, reviews, and commit details no longer
flatten rich content into inert or plain text. They now share the
message markdown and media pipeline, preserving NIP-92 `imeta` metadata
so links, images, and videos render consistently.

Commit bodies are fetched only when a single-commit detail view is
opened, keeping list queries lightweight while exposing full context
beside the diff.

### Related issue

None found.

### Testing

- Pre-push suite: `desktop-check`, `desktop-test`, `desktop-tauri-test`,
`rust-tests`, and `mobile-test`
- Project issue and pull request regression tests cover preserving
attachment metadata on roots, updates, and comments
- The project commit detail smoke scenario verifies linked text, images,
and video in commit bodies

Signed-off-by: Thomas Petersen <thomasp@squareup.com>

desktop/src/shared/api/projectGit.ts

@@ -116,6 +116,7 @@ type RawProjectRepoDiff = {
   files: RawProjectRepoDiffFile[];
   additions: number;
   deletions: number;
+  commit_body: string | null;
 };
 
 function fromRawProjectRepoSnapshot(
@@ -192,6 +193,7 @@ export async function getProjectRepoDiff(input: {
   return {
     additions: diff.additions,
     deletions: diff.deletions,
+    commitBody: diff.commit_body,
     files: diff.files.map((file) => ({
       path: file.path,
       additions: file.additions,
@@ -227,6 +229,7 @@ export async function getProjectLocalRepoDiff(input: {
   return {
     additions: diff.additions,
     deletions: diff.deletions,
+    commitBody: diff.commit_body,
     files: diff.files.map((file) => ({
       path: file.path,
       additions: file.additions,

desktop/src/shared/api/projectGitTypes.ts

@@ -43,6 +43,7 @@ export type ProjectRepoDiff = {
   files: ProjectRepoDiffFile[];
   additions: number;
   deletions: number;
+  commitBody: string | null;
 };
 
 export type ProjectLocalRepoSnapshot = {