Rewrite posting skill to be location-agnostic

The skill was authored in this dev workspace, where the Daybook server,
the skill, and the posting agent all share one directory — so it read as
if the agent always runs from a Daybook source checkout on localhost.

- State up front that you post to a running instance that may be anywhere,
  need no source checkout, and are tied to it only via DAYBOOK_URL/TOKEN.
- Drop "from the project root"; reference the bundled helper by absolute
  path (DAYBOOK_POST=.../this-skill/scripts/daybook_post.py).
- Reframe DAYBOOK_URL as set-this-to-your-instance; label 127.0.0.1:8001
  as the local dev fallback only.
- Genericize the hardcoded localhost URL in the image-embed example.
- Add a raw curl fallback for environments without the Python helper.
- Keep frontmatter to name+description (the Skills-API-portable subset).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

skills/daybook-posting/SKILL.md

@@ -1,26 +1,13 @@
 ---
 name: daybook-posting
-description: Use when you have produced a finished deliverable such as a report, summary, brief, diagram, generated HTML, PDF, deck, or status update that a human should review later outside this chat. Publishes the artifact to Daybook and returns a URL.
+description: Use when you have produced a finished deliverable such as a report, summary, brief, diagram, generated HTML, PDF, deck, or status update that a human should review later outside this chat. Publishes the artifact to a Daybook instance and returns a URL.
 ---
 
 # Daybook Posting
 
 Daybook is a private artifact journal for completed agent outputs. It stores, indexes, and displays artifacts for human review. It does not execute commands, run workflows, or continue conversations.
 
-Always use the helper script. Do not hand-build curl, JSON, PowerShell multipart, or inline shell content.
+You post to a **running Daybook server**, which may be anywhere — a cloud VM, a container, or a workstation. You do **not** need a checkout of Daybook's source. The only things that tie you to a particular instance are two environment variables: `DAYBOOK_URL` (where the server is) and `DAYBOOK_TOKEN` (who you are). Set those and the rest of this skill works unchanged regardless of where you or the server run.
-
-From the project root:
-
-```bash
-python skills/daybook-posting/scripts/daybook_post.py --check
-python skills/daybook-posting/scripts/daybook_post.py --kind markdown --title "Build Report" --content-file report.md
-cat report.md | python skills/daybook-posting/scripts/daybook_post.py --kind markdown --title "Build Report"
-python skills/daybook-posting/scripts/daybook_post.py --file diagram.svg --title "Architecture Diagram"
-```
-
-The project also keeps a compatibility wrapper at `scripts/daybook_post.py`, but the canonical helper is bundled inside this skill.
-
-The artifact URL is printed as the final stdout line.
 
 ## Configuration
 
@@ -30,12 +17,54 @@ config) — the helper reads `os.environ` directly. There is no `.env` file
 support; a `.env` file in the working directory is not read automatically.
 
 ```text
-DAYBOOK_URL=http://127.0.0.1:8001
+DAYBOOK_URL=https://your-daybook-instance.example.com   # your server's base URL
-DAYBOOK_TOKEN=your-personal-api-token
+DAYBOOK_TOKEN=your-personal-api-token                   # from Settings -> Account
-DAYBOOK_SOURCE=agent
+DAYBOOK_SOURCE=agent                                    # a stable label for what's posting
 ```
 
-`DAYBOOK_TOKEN` is your personal per-user API token, from Settings → Account in the app (not a token shared by everyone). Artifacts posted with your token land only in your feed.
+- **`DAYBOOK_URL`** — the base URL of the Daybook instance you're posting to.
+  Set it to your server. If it's unset, the helper falls back to
+  `http://127.0.0.1:8001`, which is only correct when Daybook is running
+  locally on the same machine (its development default). For any remote or
+  deployed instance you **must** set this.
+- **`DAYBOOK_TOKEN`** — your personal per-user API token, from Settings →
+  Account in the app (not a token shared by everyone). Artifacts posted with
+  your token land only in your feed.
+- **`DAYBOOK_SOURCE`** — a free-text label for whatever is posting
+  (agent-profile, script, or person name). Optional; can also be passed per
+  call with `--source`.
+
+## The Helper
+
+Always use the bundled helper script. Do not hand-build curl, JSON,
+PowerShell multipart, or inline shell content (a `curl` fallback for
+environments without the helper is documented at the end — the script is
+still preferred everywhere it's available).
+
+The helper lives at **`scripts/daybook_post.py` inside this skill's own
+directory** — not in any project you happen to be working in. Invoke it by
+its absolute path. For brevity, the examples below assume you've captured
+that path once:
+
+```bash
+# Point this at the helper inside THIS skill directory (absolute path).
+DAYBOOK_POST=/abs/path/to/this/skill/scripts/daybook_post.py
+```
+
+Then:
+
+```bash
+python "$DAYBOOK_POST" --check
+python "$DAYBOOK_POST" --kind markdown --title "Build Report" --content-file report.md
+cat report.md | python "$DAYBOOK_POST" --kind markdown --title "Build Report"
+python "$DAYBOOK_POST" --file diagram.svg --title "Architecture Diagram"
+```
+
+The artifact URL is printed as the final stdout line.
+
+(If you *are* working inside a Daybook source checkout, a compatibility
+wrapper also exists at `scripts/daybook_post.py` in the repo root, but the
+canonical helper is the one bundled in this skill.)
 
 ## Kind Cheat Sheet
 
@@ -65,8 +94,9 @@ presentation.
 
 This script only **creates** artifacts — none of the following are
 possible through it. Updating an existing artifact's title/tags/metadata,
-or deleting one, requires the raw API (see `docs/api.md`); enabling its
+or deleting one, requires the raw API (see the instance's `docs/api.md` or
-public share link is feed-UI-only, with no API equivalent at all yet.
+`GET /api/capabilities`); enabling its public share link is feed-UI-only,
+with no API equivalent at all yet.
 
 ## CDN Snippets For `html_full`
 
@@ -119,11 +149,12 @@ artifact), upload it first and reference the returned URL:
 
 ```bash
 # 1. Upload -> prints the URL as the last line
-python skills/daybook-posting/scripts/daybook_post.py --upload-image chart.png
+python "$DAYBOOK_POST" --upload-image chart.png
 
-# 2. Reference that URL in your markdown, then post as usual
+# 2. Reference that URL in your markdown, then post as usual.
-#    ![chart](http://127.0.0.1:8001/assets/ab12cd34ef56)
+#    The printed URL is absolute against your DAYBOOK_URL, e.g.
-python skills/daybook-posting/scripts/daybook_post.py report.md
+#    ![chart]($DAYBOOK_URL/assets/ab12cd34ef56)
+python "$DAYBOOK_POST" report.md
 ```
 
 The image is linked to the artifact that references it and is deleted along with it.
@@ -136,19 +167,19 @@ just post the file positionally; auto-mode detects `.csv`/`.json` and picks
 the right kind automatically:
 
 ```bash
-python skills/daybook-posting/scripts/daybook_post.py results.csv
+python "$DAYBOOK_POST" results.csv
-python skills/daybook-posting/scripts/daybook_post.py --kind json --title "Run Summary" --content-file summary.json
+python "$DAYBOOK_POST" --kind json --title "Run Summary" --content-file summary.json
 ```
 
 `.xlsx` spreadsheets work too, with no special flag needed — just `--file`
 (or post it positionally, same as any other file):
 
 ```bash
-python skills/daybook-posting/scripts/daybook_post.py balance_sheet.xlsx
+python "$DAYBOOK_POST" balance_sheet.xlsx
 ```
 
 The server converts it to a `csv` artifact automatically. Known
-limitations (see `docs/api.md` for the full list):
+limitations (see the instance's `docs/api.md` for the full list):
 
 - Only the workbook's **active sheet** converts; other sheets are dropped.
 - Formula cells need to have been calculated and saved by real spreadsheet
@@ -165,7 +196,7 @@ as a binary, use `--file path --as-markdown` to wrap it in a Markdown
 fenced code block (still gets syntax highlighting):
 
 ```bash
-python skills/daybook-posting/scripts/daybook_post.py --file script.py --as-markdown --title "Generated Script"
+python "$DAYBOOK_POST" --file script.py --as-markdown --title "Generated Script"
 ```
 
 Without `--as-markdown`, it uploads as a downloadable binary file instead.
@@ -189,8 +220,37 @@ context like `run_id` or `model` — these end up in the artifact's
 ## Rules
 
 - Run `--check` first if unsure Daybook is reachable.
+- Make sure `DAYBOOK_URL` points at the right instance and `DAYBOOK_TOKEN` is set before posting anything real.
 - Use a stable `DAYBOOK_SOURCE` or pass `--source` (the agent-profile, script, or person name that produced this artifact).
 - Use `--tags a,b,c` for filtering.
 - Use `--meta run_id=... --meta model=...` for machine-readable context.
 - Never inline multiline content into the shell command; use a file or stdin.
 - Add `--dry-run` to see exactly what would be sent (method, headers, payload) without actually posting — useful when unsure a payload is well-formed.
+
+## `curl` Fallback (No Helper Available)
+
+Prefer the helper above — it handles multipart, content-type inference,
+JSON shaping, and provenance flags for you. Use raw `curl` **only** when you
+genuinely can't run the bundled Python script (e.g. a minimal environment
+with no Python). Text artifacts post as JSON to `POST /api/artifacts` with
+bearer-token auth:
+
+```bash
+curl -sS -X POST "$DAYBOOK_URL/api/artifacts" \
+  -H "Authorization: Bearer $DAYBOOK_TOKEN" \
+  -H "Content-Type: application/json" \
+  -d '{"kind":"markdown","title":"Build Report","source":"agent","content":"# Hello\n\nBody text."}'
+```
+
+File/image artifacts use multipart instead:
+
+```bash
+curl -sS -X POST "$DAYBOOK_URL/api/artifacts" \
+  -H "Authorization: Bearer $DAYBOOK_TOKEN" \
+  -F "kind=image" -F "title=Architecture Diagram" -F "source=agent" \
+  -F "file=@diagram.png"
+```
+
+`GET $DAYBOOK_URL/api/capabilities` (no auth needed beyond a login/token per
+that instance's config) lists supported kinds, methods, and the server
+version if you need to confirm the contract before posting.