feat: v8.0.0 — first agent template (PM Sprint Agent) following Anthropic's agent template architecture

- Added templates/pm-sprint-agent/ directory with full agent template
  - AGENT.md system prompt with explicit step-by-step workflow
  - 2 subagents: capacity-analyst and risk-scorer
  - 2 connectors: linear and jira (with example configs)
  - Symlinked skills from main library: sprint-planning, sprint-brief
  - orchestrate.sh end-to-end workflow script
  - examples/ folder with input and output examples
  - tests/ folder with smoke test
- Updated README to position skills as building blocks for agent templates
- Added Anthropic agent templates announcement reference (May 5, 2026)
- Bumped marketplace.json to v8.0.0
- Listed 7 candidate agent templates this library supports

This is the first agent template in the library. More to follow.

templates/pm-sprint-agent/examples/input-example.md

@@ -0,0 +1,97 @@
+# Example: Input to the PM Sprint Agent
+
+This is what you provide when running the agent. Use this as a reference for what to pass in real usage.
+
+## Command-line invocation
+
+```bash
+bash orchestrate.sh \
+  --sprint-goal "Reduce checkout abandonment by 20%" \
+  --sprint-number 23 \
+  --team-size 5 \
+  --duration-weeks 2 \
+  --capacity-buffer 0.2 \
+  --include-bugs true \
+  --post-to-slack true
+```
+
+## What the agent reads from your connector
+
+The agent automatically pulls these from Linear or Jira — you don't need to provide them:
+
+### From the ticketing system
+- All open issues in the configured project, filtered by:
+  - State: backlog or ready (not "in progress" or "done")
+  - Not already assigned to an active sprint
+  - Tagged with the sprint goal scope (if such tags exist)
+- For each issue:
+  - Title and description
+  - Story point estimate
+  - Priority
+  - Assignee (if any)
+  - Dependencies and blockers
+  - Recent comments
+  - Labels and components
+
+### From the team's velocity history
+- Story points completed in each of the last 3 sprints
+- Items that slipped from the last 3 sprints
+- Average issue size and standard deviation
+
+### From the team's calendar (if calendar integration is set up)
+- PTO entries for the upcoming sprint window
+- Public holidays affecting the team
+- Conferences or training days
+- Known on-call rotations
+
+## What the agent does NOT need from you
+
+You do NOT need to provide:
+- A list of items to include — the agent picks based on capacity and priority
+- Story point estimates — the agent uses what's already in the ticketing system
+- Risk assessments — the agent generates these
+- Brief content — the agent generates this from the plan
+
+If items don't have story point estimates, the agent will flag this and ask you to estimate before continuing.
+
+## What the agent expects you to know
+
+You should be able to answer:
+
+- **What is the sprint goal?** A single-sentence outcome the team is committing to.
+- **Which sprint number is this?** Used for tracking and continuity.
+- **How big is the team?** Number of engineers actually working on the sprint.
+- **How long is the sprint?** Usually 1 or 2 weeks.
+
+If you're not sure of any of these, the agent will ask. But the workflow is fastest when you know them upfront.
+
+## Example: Real-world invocation
+
+```bash
+# Standard 2-week sprint with default settings
+bash orchestrate.sh \
+  --sprint-goal "Ship the new pricing page A/B test" \
+  --sprint-number 47
+
+# Small team, 1-week sprint
+bash orchestrate.sh \
+  --sprint-goal "Fix high-priority bugs before launch" \
+  --sprint-number 48 \
+  --team-size 3 \
+  --duration-weeks 1 \
+  --include-bugs true
+
+# Larger team, with conservative buffer
+bash orchestrate.sh \
+  --sprint-goal "Migrate authentication to new identity provider" \
+  --sprint-number 49 \
+  --team-size 8 \
+  --capacity-buffer 0.3 \
+  --include-bugs false
+
+# Dry run to validate config without executing
+bash orchestrate.sh \
+  --sprint-goal "Test sprint" \
+  --sprint-number 99 \
+  --dry-run
+```