FE: Apply / Join / Claim flow (mode-aware) + edit/withdraw application

[0xdevcollins]

Context

Part of the Bounty Builder Lifecycle milestone (v1 boundless). The entry action differs across the six modes: claim (open + single claim), join (open + competition), or an application (application_light / application_full).

Tasks

• Application form (application_light / application_full): proposalShort or proposalFull, portfolioLinks, estimatedDays, qualifications, videoIntroUrl per entry type (light: short proposal + estimate; full: full proposal + qualifications + optional video). POST v2/applications; edit (PATCH) and withdraw (DELETE) while SUBMITTED.
• Join open competition: POST v2/competition/join; leave: DELETE.
• Open + single claim: on-chain claim via the apply escrow op (useEscrowOpRunner, default MANAGED) + progress UI; withdraw-application escrow op.
• Surface reputation / application-credit pre-checks before submitting.

Blueprint to mirror

• components/hackathons/submissions/SubmissionForm.tsx (form patterns); the escrow runner + progress dialog.

Acceptance criteria

• Each mode's entry works end to end; edit/withdraw (application) and leave (competition) work.

Depends on

• Bounty data layer; detail page.

[linear]

BOU-273

[Ojas2095]

/claim

I'd like to take this on! Reviewing the repository right now and will submit a PR shortly.

[coderabbitai]

🔗 Related PRs

#451 - UI fixes [merged]
#547 - fix(submissions): improve link validation UX, banner display, and error toasts [merged]
#555 - feat(hackathons): add "hidden until results" submission visibility mode [merged]
#582 - fix(rewards): match track winners by submissionId, not participantId [merged]
#586 - fix(submissions): unbreak submission detail page + publish hackathon recap [merged]

---

📝 Issue Planner

_{Check the box below or use the @coderabbitai plan command to generate an implementation plan and prompts that you can use with your favorite coding assistant.}

• Create Plan

---

🧪 Issue enrichment is currently in open beta.

You can configure auto-planning by selecting labels in the issue_enrichment configuration.

To disable automatic issue enrichment, add the following to your .coderabbit.yaml:

issue_enrichment:
  auto_enrich:
    enabled: false

💬 Have feedback or questions? Drop into our discord!

[Rachaelisa]

/attempt #624

I'd like to take this on! Reviewing the repository right now and will submit a PR shortly.