Publish AGENTS.md and trim it to technical content

[rickdijk]

✨ What kind of change does this PR introduce? (Bug fix, feature, docs update...)

Docs. Implements FPL-6.

Stacked on #522 (FPL-5), which FPL-6 is blocked by. Base retargets to develop once #522 merges.

⤵️ What is the current behavior?

Two problems.

AGENTS.md is git-ignored (6292965), so the best documentation in this repo is local to one checkout — absent from every clone and from CI, and CLAUDE.md's @AGENTS.md import resolves to nothing for anyone else.

It is also 205 lines mixing three different kinds of content: technical reference a contributor needs, process rules stated as prose an agent may or may not honour, and internal Baseflow strategy.

🆕 What is the new behavior (if this is a feature change)?

AGENTS.md is un-ignored and committed, then trimmed 205 → 188 lines, split by what each part does.

Stays — the technical reference that turns a stalled contributor into a merged PR: architecture overview, directory map, where-to-make-changes map, fork workflow, commands, testing expectations, platform notes, PR checklist.

Leaves, with a destination — nothing is deleted outright:

• The "do not force-push / do not bump versions / do not commit unless asked" rules are parked verbatim on FPL-8, where they become PreToolUse hooks that block rather than advise.
• The Notion link and internal Baseflow strategy are parked verbatim on FPL-12, bound for the private maintenance repo.

CLAUDE.md drops its note that the import is a no-op, which this change makes untrue.

The section order is chosen to be portable to octo_image and flutter_cached_network_image (FPL-10 / FPL-11 depend on this shape).

💥 Does this PR introduce a breaking change?

No. Documentation only — no package code is touched.

🐛 Recommendations for testing

The check that matters is that the import resolves for someone other than the author:

git clone --branch chore/fpl-6-agents-md-technical <repo> /tmp/probe
ls /tmp/probe/AGENTS.md    # present, 188 lines
head -1 /tmp/probe/CLAUDE.md    # @AGENTS.md

Verified locally: fresh clone contains both files. dart format --set-exit-if-changed . clean (56 files, 0 changed). flutter analyze reports 2 pre-existing use_super_parameters info lints in lib/src/web/web_helper.dart:242 and test/cache_manager_test.dart:626, both in files this PR does not touch.

📝 Links to relevant issues/docs

• FPL-6 — the ticket this implements
• FPL-8 — holds the hook-bound rules
• FPL-12 — holds the private-repo-bound content
• Reverses 6292965 ("Ignore local AGENTS.md agent instruction files")

🤔 Checklist before submitting

• All projects build (no code changes)
• Follows style guide lines (code style guide)
• Relevant documentation was updated
• Rebased onto current develop (via Add root CLAUDE.md importing local AGENTS.md #522)

🤖 Generated with Claude Code