feat(cli): image pasting support via Ctrl+V and /paste command

[Stranmor]

Closes #2811

This PR adds support for inserting images directly into the chat prompt from the clipboard.

Features

• Binds Ctrl+V in the prompt to read an image from the clipboard.
• Adds /paste slash command as an alternative way to paste images.
• Images are saved as PNG in ~/.local/share/forge/images and inserted as @[/path/to/image.png].
• Implements a robust clipboard fetching fallback:
  1. Tries native Wayland/X11 tools (wl-paste, xclip) for accurate pixel extraction.
  2. Falls back to arboard if native tools aren't present.
  3. Checks if the clipboard contains file URIs (file://...) or absolute paths if the user copied image files directly from a file manager.

[CLAassistant]

All committers have signed the CLA.

[graphite-app]

Slice indexing panic when line is a single quote character

If the clipboard contains a single " or ' character, this code will panic at runtime with an index out of bounds error.

When line = "\"" (length 1):

• line.starts_with('"') returns true
• line.ends_with('"') returns true
• &line[1..line.len() - 1] becomes &line[1..0], which is an invalid slice range

Fix:

let line = if line.len() >= 2 && ((line.starts_with('"') && line.ends_with('"'))
    || (line.starts_with('\'') && line.ends_with('\''))) 
{
    &line[1..line.len() - 1]
} else {
    line
};

Suggested change

	let line = if (line.starts_with('"') && line.ends_with('"'))
	|| (line.starts_with('\'') && line.ends_with('\''))
	{
	&line[1..line.len() - 1]
	} else {
	line
	};
	let line = if line.len() >= 2 && ((line.starts_with('"') && line.ends_with('"'))
	|| (line.starts_with('\'') && line.ends_with('\'')))
	{
	&line[1..line.len() - 1]
	} else {
	line
	};

Spotted by Graphite



Is this helpful? React 👍 or 👎 to let us know.

[graphite-app]

Debug logging code was left in production. This will create and append to /tmp/forge_paste.log on every Ctrl+V press, causing unnecessary disk I/O and potential disk space issues over time.

// Remove this debug code block entirely:
if let Ok(mut f) = std::fs::OpenOptions::new()
    .create(true)
    .append(true)
    .open("/tmp/forge_paste.log")
{
    let _ = writeln!(&mut f, "Received !forge_internal_paste_image");
    use std::io::Write;
}

Spotted by Graphite



Is this helpful? React 👍 or 👎 to let us know.

[graphite-app]

Cross-platform compatibility issue. Using HOME environment variable with /tmp fallback will fail on Windows where neither exists. The path /tmp doesn't exist on Windows and would cause directory creation to fail, breaking the paste functionality.

// Use platform-appropriate directories:
let home_dir = if cfg!(windows) {
    std::env::var("USERPROFILE").unwrap_or_else(|_| std::env::var("TEMP").unwrap_or_else(|_| "C:\\Temp".to_string()))
} else {
    std::env::var("HOME").unwrap_or_else(|_| "/tmp".to_string())
};

Suggested change

	let home_dir = std::env::var("HOME").unwrap_or_else(|_| "/tmp".to_string());
	let home_dir = if cfg!(windows) {
	std::env::var("USERPROFILE").unwrap_or_else(|_| {
	std::env::var("TEMP").unwrap_or_else(|_| "C:\\Temp".to_string())
	})
	} else {
	std::env::var("HOME").unwrap_or_else(|_| "/tmp".to_string())
	};

Spotted by Graphite



Is this helpful? React 👍 or 👎 to let us know.

[graphite-app]

The cache behavior has changed from caching file contents to only caching file paths. This means files are re-read from disk on every get_custom_instructions() call instead of being cached in memory. While this may be intentional to pick up file changes, it significantly reduces cache effectiveness and introduces repeated file I/O.

If the old caching behavior is desired, the cache type should remain Vec<String> and cache the actual content:

cache: tokio::sync::OnceCell<Vec<String>>,

async fn init(&self) -> Vec<String> {
    let paths = self.discover_agents_files().await;
    let mut custom_instructions = Vec::new();
    for path in paths {
        if let Ok(content) = self.infra.read_utf8(&path).await {
            custom_instructions.push(content);
        }
    }
    custom_instructions
}

async fn get_custom_instructions(&self) -> Vec<String> {
    self.cache.get_or_init(|| self.init()).await.clone()
}

Suggested change

	async fn get_custom_instructions(&self) -> Vec<String> {
	let paths = self.cache.get_or_init(|| self.discover_agents_files()).await;
	let mut custom_instructions = Vec::new();
	for path in paths {
	if let Ok(content) = self.infra.read_utf8(&path).await {
	if let Ok(content) = self.infra.read_utf8(path).await {
	custom_instructions.push(content);
	}
	}
	async fn get_custom_instructions(&self) -> Vec<String> {
	self.cache.get_or_init(|| async {
	let paths = self.discover_agents_files().await;
	let mut custom_instructions = Vec::new();
	for path in paths {
	if let Ok(content) = self.infra.read_utf8(&path).await {
	custom_instructions.push(content);
	}
	}
	custom_instructions
	}).await.clone()
	}

Spotted by Graphite



Is this helpful? React 👍 or 👎 to let us know.