Restructure as a self-contained Agent Skills package (fix Codex install)

Move the skill into skills/watch/ so SKILL.md and its scripts/ runtime are
siblings inside one folder. `npx skills add` (Codex/Cursor/Copilot/agents) now
copies a working skill as a unit; previously it grabbed the root SKILL.md alone
and left scripts/ behind, so the skill was dead on arrival on every non-Claude
host. Mirrors the layout last30days-skill adopted for the same reason.

- skills/watch/{SKILL.md,scripts/}: self-contained skill folder
- SKILL.md: resolve a harness-agnostic $SKILL_DIR (the dir it was Read from)
  instead of the Claude-Code-only ${CLAUDE_SKILL_DIR}; guard + 19 call sites
- drop commands/watch.md: /watch derives from frontmatter (name + user-invocable)
- .codex-plugin/plugin.json: full manifest with "skills": "./skills/" + interface
- add .agents/plugins/marketplace.json, AGENTS.md, CLAUDE.md, .skillignore
- build-skill.sh: archive the skills/watch subtree (one SKILL.md, no zip -d)
- fix paths in tests, hooks hint, .gitattributes, release.yml
- relocate dev-sync.sh to repo root and fix REPO_ROOT
- README: content-ideas structure, npx skills install, star history

Verified: 37/37 tests pass; npx skills add bundles the full scripts/ runtime;
manifests valid; versions synced at 0.1.3.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

skills/watch/scripts/config.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+"""Shared /watch configuration helpers."""
+from __future__ import annotations
+
+import os
+from pathlib import Path
+
+
+CONFIG_DIR = Path.home() / ".config" / "watch"
+CONFIG_FILE = CONFIG_DIR / ".env"
+
+DEFAULT_DETAIL = "balanced"
+
+DETAILS = {"transcript", "efficient", "balanced", "token-burner"}
+
+
+def read_env_file(path: Path | None = None) -> dict[str, str]:
+    if path is None:
+        path = CONFIG_FILE
+    values: dict[str, str] = {}
+    if not path.exists():
+        return values
+    try:
+        lines = path.read_text(encoding="utf-8").splitlines()
+    except OSError:
+        return values
+    for line in lines:
+        raw = line.strip()
+        if not raw or raw.startswith("#") or "=" not in raw:
+            continue
+        key, _, value = raw.partition("=")
+        value = value.strip()
+        if len(value) >= 2 and value[0] in ('"', "'") and value[-1] == value[0]:
+            value = value[1:-1]
+        values[key.strip()] = value
+    return values
+
+
+def get_config() -> dict[str, object]:
+    file_values = read_env_file()
+
+    detail = (
+        os.environ.get("WATCH_DETAIL")
+        or file_values.get("WATCH_DETAIL")
+        or DEFAULT_DETAIL
+    )
+    if detail not in DETAILS:
+        detail = DEFAULT_DETAIL
+
+    return {
+        "detail": detail,
+        "config_file": str(CONFIG_FILE),
+    }
+
+
+def frame_cap(detail: str) -> int | None:
+    if detail == "efficient":
+        return 50
+    if detail == "balanced":
+        return 100
+    if detail == "token-burner":
+        return None
+    if detail == "transcript":
+        return None
+    return 100