docs: add telemetry marker workflow (#9543)

## Thinking Path

> - Paperclip is an open-source agentic AI management platform that
ships anonymous usage telemetry to understand product health and
adoption.
> - The telemetry system has a generated contract
(`packages/shared/src/telemetry/generated/paperclip-telemetry.ts`) that
types every first-party event the product emits.
> - When a product change needs a new first-party event that is not yet
in the generated contract, contributors had no public workflow
explaining how to propose an event or later promote it into the contract
once accepted.
> - The gap leads to confusion at call sites: contributors either skip
tracking entirely or emit untyped events that bypass the privacy and
governance safeguards built into the contract.
> - This PR fills that gap by adding `doc/TELEMETRY_WORKFLOW.md` — a
public contributor guide that covers the full propose → promote
lifecycle: the `@ts-expect-error -- proposed-telemetry(...)` marker, the
canonical multi-line `track()` shape, the TS2578 expiry signal, and the
look-up-by-event-name promotion step.
> - `packages/shared/src/telemetry/README.md` gains a cross-reference so
readers of the data-contract doc can find the workflow guide without
searching.
> - `README.md` gains a one-line pointer in the telemetry section so the
workflow is discoverable from the project entry point.

## Linked Issues or Issue Description

No pre-existing public GitHub issue covers this doc gap. Inline
description:

**Problem:** Contributors adding product telemetry for events not yet in
the generated contract have no documented workflow. The
`@ts-expect-error -- proposed-telemetry(...)` pattern exists in the
codebase but is undocumented, leading to inconsistent usage and missing
adoption signals.

**Solution:** A new public guide (`doc/TELEMETRY_WORKFLOW.md`) documents
the marker format, the recommended multi-line `track()` shape that
preserves the TS2578 expiry signal, the dimension rules, and the
promotion checklist. Cross-references are added to
`packages/shared/src/telemetry/README.md` and the top-level `README.md`.

No related open PRs found.

## What Changed

- **New file `doc/TELEMETRY_WORKFLOW.md`** — public contributor guide
for the propose/promote lifecycle: marker format, canonical multi-line
example, TS2578 single-line trap, dimension rules, and step-by-step
promotion checklist.
- **`packages/shared/src/telemetry/README.md`** — added one-line
cross-reference pointing at `doc/TELEMETRY_WORKFLOW.md` for proposed
events not yet in the generated contract.
- **`README.md`** — added one-line pointer in the telemetry section so
the new workflow guide is reachable from the top-level project entry.

## Verification

This is a docs-only change. Verification steps:

1. Open `doc/TELEMETRY_WORKFLOW.md` and confirm it contains:
   - The `^[a-z0-9][a-z0-9._:-]{1,63}$` event-name grammar.
- The exact `// @ts-expect-error -- proposed-telemetry(<issue>):
<rationale>` marker.
- The multi-line `client.track()` copy-paste example (directive on line
before event-name string).
- The explanation of the TS2578 single-line trap and the
look-up-by-event-name step.
   - The promotion checklist in the "Promote An Event" section.
2. Confirm `packages/shared/src/telemetry/README.md` cross-references
`doc/TELEMETRY_WORKFLOW.md`.
3. Confirm the `README.md` telemetry section links to
`doc/TELEMETRY_WORKFLOW.md`.

## Risks

Low risk — docs-only change. No runtime behavior, schema, or existing
telemetry emission is affected. The risk is that the guidance could
diverge from the actual enforcement in the codebase over time; mitigated
by linking to the generated contract and keeping the doc in the same
repo.

## Model Used

Claude — `claude-sonnet-4-6` (Anthropic Claude Sonnet 4.6). Tool use
enabled. Extended context. Produced via the Paperclip agentic workflow
with `Co-authored-by: Paperclip <noreply@paperclip.ing>`.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

Co-authored-by: Paperclip <noreply@paperclip.ing>

README.md

@@ -410,6 +410,7 @@ Paperclip ships with opt-in OpenTelemetry auto-instrumentation for the server (t
 Paperclip collects anonymous usage telemetry to help us understand how the product is used and improve it. No personal information, issue content, prompts, file paths, or secrets are ever collected. Private repository references are hashed with a per-install salt before being sent.
 
 Contributors changing emitted telemetry events should follow the [Telemetry Data Contract](packages/shared/src/telemetry/README.md).
+For proposed first-party events that are not in the generated contract yet, follow [Telemetry Workflow](doc/TELEMETRY_WORKFLOW.md).
 
 Telemetry is **enabled by default** and can be disabled with any of the following:
 

packages/shared/src/telemetry/README.md

@@ -122,6 +122,10 @@ Before opening a pull request, verify that the emitted code, typed helpers, and
 generated telemetry contract agree. If they disagree, fix the contract or code
 rather than documenting around the mismatch in this README.
 
+For new first-party events that are not in the generated contract yet, follow
+the public proposal and promotion workflow in
+[`doc/TELEMETRY_WORKFLOW.md`](../../../../doc/TELEMETRY_WORKFLOW.md).
+
 ## Retention
 
 Retention windows are documented in `retention.ts`. Each event is assigned a