feat(cli): add pic triggers + dead-letters + secrets subcommands

Closes the audit's High-severity CLI coverage gap, raising the count
from ~25 to ~40+ subcommands and bringing the integration test count
from 63 to 73.

- pic triggers {ls, rm, create-kv, create-cron, create-dead-letter,
  create-from-json}: three per-kind wrappers cover the most common
  trigger shapes; the generic create-from-json is the escape hatch
  for docs/files/pubsub/email/queue and any future advanced retry
  knobs — body JSON inline, via @<file>, or "-" for stdin.

- pic dead-letters {ls, show, replay, resolve}: full operator
  workflow for the dispatcher's dead_letters rows, including the
  --unresolved filter and the per-row replay + manual-resolve actions.

- pic secrets {ls, set, rm}: list names + updated_at, set values
  via stdin (the only secure channel — inline values would leak
  into shell history), and delete by name. --json on set treats
  stdin as raw JSON for non-string values.

Ten new integration tests follow the established #[ignore] pattern,
gated on DATABASE_URL. All 73 ignored tests pass against the local
dev stack.

The `pic admin reset-password` server-binary subcommand exists on
the picloud binary side already; the audit's "surface it in pic
--help" note is a one-line addition deferred to Stage 6 with the
other small UX touches.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/picloud-cli/src/cmds/dead_letters.rs

@@ -0,0 +1,95 @@
+//! `pic dead-letters` subcommands: `ls`, `show`, `replay`, `resolve`.
+
+use anyhow::Result;
+
+use crate::client::Client;
+use crate::config;
+use crate::output::{KvBlock, OutputMode, Table};
+
+pub async fn ls(app: &str, unresolved: bool, limit: u32, mode: OutputMode) -> Result<()> {
+    let creds = config::resolve()?;
+    let client = Client::from_creds(&creds)?;
+    let resp = client.dead_letters_list(app, unresolved, limit).await?;
+    let mut table = Table::new([
+        "id",
+        "source",
+        "op",
+        "attempts",
+        "resolved",
+        "last_error",
+        "created_at",
+    ]);
+    for d in resp.dead_letters {
+        let last_err = truncate(&d.last_error, 60);
+        let resolved = d.resolution.unwrap_or_else(|| "-".into());
+        table.row([
+            d.id,
+            d.source,
+            d.op,
+            d.attempt_count.to_string(),
+            resolved,
+            last_err,
+            d.created_at.to_rfc3339(),
+        ]);
+    }
+    table.print(mode);
+    Ok(())
+}
+
+pub async fn show(app: &str, dl_id: &str, mode: OutputMode) -> Result<()> {
+    let creds = config::resolve()?;
+    let client = Client::from_creds(&creds)?;
+    let d = client.dead_letters_get(app, dl_id).await?;
+    let mut block = KvBlock::new();
+    block
+        .field("id", d.id)
+        .field("source", d.source)
+        .field("op", d.op)
+        .field("trigger_id", d.trigger_id.unwrap_or_else(|| "-".into()))
+        .field(
+            "script_id",
+            d.script_id
+                .map(|s| s.to_string())
+                .unwrap_or_else(|| "-".into()),
+        )
+        .field("attempt_count", d.attempt_count.to_string())
+        .field("first_attempt_at", d.first_attempt_at.to_rfc3339())
+        .field("last_attempt_at", d.last_attempt_at.to_rfc3339())
+        .field("last_error", d.last_error)
+        .field("created_at", d.created_at.to_rfc3339())
+        .field(
+            "resolved_at",
+            d.resolved_at
+                .map(|t| t.to_rfc3339())
+                .unwrap_or_else(|| "-".into()),
+        )
+        .field("resolution", d.resolution.unwrap_or_else(|| "-".into()))
+        .field("payload", d.payload.to_string());
+    block.print(mode);
+    Ok(())
+}
+
+pub async fn replay(app: &str, dl_id: &str) -> Result<()> {
+    let creds = config::resolve()?;
+    let client = Client::from_creds(&creds)?;
+    client.dead_letters_replay(app, dl_id).await?;
+    println!("Replayed dead-letter {dl_id}");
+    Ok(())
+}
+
+pub async fn resolve(app: &str, dl_id: &str, reason: &str) -> Result<()> {
+    let creds = config::resolve()?;
+    let client = Client::from_creds(&creds)?;
+    client.dead_letters_resolve(app, dl_id, reason).await?;
+    println!("Resolved dead-letter {dl_id}: {reason}");
+    Ok(())
+}
+
+fn truncate(s: &str, max: usize) -> String {
+    if s.chars().count() <= max {
+        return s.to_string();
+    }
+    let mut out: String = s.chars().take(max.saturating_sub(1)).collect();
+    out.push('…');
+    out
+}