docs(projects): warn that Linear's API rejects emoji for --icon (#147)

* docs(projects): warn that Linear's API rejects emoji for --icon

Linear's GraphQL schema docstring claims project icons accept emoji or
icon names, but the upstream server-side validator rejects emoji at
runtime with a confusing INVALID_INPUT error. Update --icon help text on
both `projects create` and `projects update` to recommend named icons
(e.g. "Computer", "Database") and call out the schema/runtime mismatch
so users — especially LLM consumers — don't get misled.

Add regression tests that assert both help screens contain the warning.

Closes #146

* docs(projects): document emoji shortcodes as a valid --icon format

Follow-up investigation found Linear's API does accept emoji — but only
as colon-wrapped shortcodes (`:repeat:`, `:computer:`), not as raw
unicode characters (🔁). Two formats work:

  - Emoji shortcodes:  `:repeat:`, `:rocket:`, `:computer:`
  - Named icons:       `Computer`, `Database`

Update --icon help to call out both formats and explicitly warn that
raw unicode emoji are rejected. Update regression tests to assert the
new wording.

Author: flipbit03

crates/lineark/src/commands/projects.rs

@@ -75,7 +75,7 @@ pub enum ProjectsAction {
         /// Markdown content for the project.
         #[arg(long)]
         content: Option<String>,
-        /// Project icon (emoji or icon name).
+        /// Project icon: an emoji shortcode like ":repeat:" (NOT raw unicode 🔁) or a Linear named icon like "Computer". Linear's API rejects raw unicode emoji.
         #[arg(long)]
         icon: Option<String>,
         /// Project color (hex color code).
@@ -131,7 +131,7 @@ pub enum ProjectsAction {
         /// Project status name or UUID.
         #[arg(long)]
         status: Option<String>,
-        /// Project icon (emoji or icon name).
+        /// Project icon: an emoji shortcode like ":repeat:" (NOT raw unicode 🔁) or a Linear named icon like "Computer". Linear's API rejects raw unicode emoji.
         #[arg(long)]
         icon: Option<String>,
         /// Project color (hex color code).

crates/lineark/tests/offline.rs

@@ -522,6 +522,60 @@ fn projects_create_help_shows_flags() {
         .stdout(predicate::str::contains("--color"));
 }
 
+/// Regression test for #146: `--icon` help text must document the two
+/// formats Linear's API actually accepts — emoji *shortcodes* (`:repeat:`)
+/// and named icons (`Computer`) — and warn that raw unicode emoji (`🔁`)
+/// are rejected at runtime despite the GraphQL schema docstring claiming
+/// otherwise. Without this, users (especially LLM consumers) reach for
+/// raw unicode and hit a confusing `INVALID_INPUT` error from the
+/// upstream validator.
+#[test]
+fn projects_create_help_icon_documents_accepted_formats() {
+    lineark()
+        .args(["projects", "create", "--help"])
+        .assert()
+        .success()
+        .stdout(predicate::str::contains(":repeat:"))
+        .stdout(predicate::str::contains("Computer"))
+        .stdout(predicate::str::contains("rejects raw unicode emoji"));
+}
+
+#[test]
+fn projects_update_help_shows_flags() {
+    lineark()
+        .args(["projects", "update", "--help"])
+        .assert()
+        .success()
+        .stdout(predicate::str::contains("--name"))
+        .stdout(predicate::str::contains("--description"))
+        .stdout(predicate::str::contains("--content"))
+        .stdout(predicate::str::contains("--lead"))
+        .stdout(predicate::str::contains("--clear-lead"))
+        .stdout(predicate::str::contains("--members"))
+        .stdout(predicate::str::contains("--team"))
+        .stdout(predicate::str::contains("--start-date"))
+        .stdout(predicate::str::contains("--clear-start-date"))
+        .stdout(predicate::str::contains("--target-date"))
+        .stdout(predicate::str::contains("--clear-target-date"))
+        .stdout(predicate::str::contains("--priority"))
+        .stdout(predicate::str::contains("--status"))
+        .stdout(predicate::str::contains("--icon"))
+        .stdout(predicate::str::contains("--color"))
+        .stdout(predicate::str::contains("--labels"));
+}
+
+/// Regression test for #146 — same documentation must appear on `update` help.
+#[test]
+fn projects_update_help_icon_documents_accepted_formats() {
+    lineark()
+        .args(["projects", "update", "--help"])
+        .assert()
+        .success()
+        .stdout(predicate::str::contains(":repeat:"))
+        .stdout(predicate::str::contains("Computer"))
+        .stdout(predicate::str::contains("rejects raw unicode emoji"));
+}
+
 #[test]
 fn projects_list_help_shows_led_by_me_flag() {
     lineark()